Harvard CS50 (2023) - Full Computer Science University Course

Learn the basics of computer science from Harvard University. This is CS50, an introduction to the intellectual enterprises of computer science and the art of programming. The course is taught live every year and this is the 2023 version.
💻 Slides, source code, and more at cs50.harvard.edu/x.
⭐️ Course Contents ⭐️
⌨️ (00:00:00) Lecture 0 - Scratch
⌨️ (02:05:47) Lecture 1 - C
⌨️ (04:35:19) Lecture 2 - Arrays
⌨️ (06:59:38) Lecture 3 - Algorithms
⌨️ (09:01:13) Lecture 4 - Memory
⌨️ (11:26:33) Lecture 5 - Data Structures
⌨️ (13:42:44) Lecture 6 - Python
⌨️ (15:58:02) Lecture 7 - SQL
⌨️ (18:18:30) Lecture 8 - HTML, CSS, JavaScript
⌨️ (20:58:14) Lecture 9 - Flask
⌨️ (23:19:07) Lecture 10 - Emoji
⌨️ (25:05:28) Cybersecurity
---
HOW TO JOIN CS50 COMMUNITIES
Discord: / discord
Ed: cs50.harvard.edu/x/ed
Facebook Group: / cs50
Faceboook Page: / cs50
GitHub: github.com/cs50
Gitter: gitter.im/cs50/x
Instagram: / cs50
LinkedIn Group: / 7437240
LinkedIn Page: / cs50
Medium: / cs50
Quora: www.quora.com/topic/CS50
Reddit: / cs50
Slack: cs50.edx.org/slack
Snapchat: / cs50
SoundCloud: / cs50
Stack Exchange: cs50.stackexchange.com/
TikTok: / cs50
Twitter: / cs50
KZbin: / cs50
HOW TO FOLLOW DAVID J. MALAN
Facebook: / dmalan
GitHub: github.com/dmalan
Instagram: / davidjmalan
LinkedIn: / malan
TikTok: / davidjmalan
Twitter: / davidjmalan
LICENSE
CC BY-NC-SA 4.0
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International Public License
creativecommons.org/licenses/...
🎉 Thanks to our Champion and Sponsor supporters:
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--
Learn to code for free and get a developer job: www.freecodecamp.org
Read hundreds of articles on programming: freecodecamp.org/news

[@user-uq6nk3fx1z]

I pause the video sometimes so he can take a break

[@emmanuelle8032]

Hahahaha ! Just 13 min in and I already thought he and I were in complete apnea ! Is this how he teach 25 hours long ? 😉

[@cynthoniashewprashad3280]

Haha. That was good. 26hrs… he’s a champ‼️

[@pcrizz]

You go to the breakroom only to find him teaching another class.

[@everythingunleashed7002]

@@pcrizz Its split into 2 hour lectures which are split throughout 3 months. He is not teaching it continously for 26 hours straight.

[@unkown110]

@@everythingunleashed7002lol he’d be dead if he did

[@stefangarces499]

24 hours of Harvard Computer Science for free?! Huge respect 🙌

[@V.D.]

First day on internet?😮

[@GooogleGoglee]

LoL ... Nothing that 1 hour of good reading on some tech blogs can tell you even better.

[@McFlashh]

@@GooogleGoglee Can you recommend some good tech blogs to read

[@V.D.]

@@GooogleGoglee yes, but there is the cs50x edX course and people say it is rather hard.

[@GooogleGoglee]

@@V.D. very generic...

[@JDP_93]

Got laid off of my construction job after working 50-60 hours a week faithfully. Now I’m going to lock down for the next year and learn the basics of coding to ultimately get a tech job. Today is day 1. Let’s go 🙏🏾

[@steveh7727]

Let's goooooo! 📈

[@ItzBakeYT]

Today, is day 13! Keep going!

[@redmachine8354]

@@ItzBakeYT He's already done

[@lucaspont6659]

so today is day 13 right?

[@tylerlashley8817]

Update?

[@jaimediez]

🎯 Key Takeaways for quick navigation: 00:00 🎓 *Introduction to the CS50 course and Dr. David Malan's background* 07:12 🛠️ *Transition to the C programming language in Week One* 18:09 🧮 *Exploring Different Number Systems* 24:29 🔢 *Introducing Volunteers to Represent Bits* 31:10 🖥️ *Bits and Bytes in Computer Memory* 36:01 📱 *Decoding Text Messages Using ASCII* 43:59 🎨 *Representation of Emojis and Skin Tones in Unicode* 46:04 🖌️ *Efficient Design in Unicode for Complex Emoji Representations* 01:17:00 🧰 *Scratch Interface and Basics* 01:25:20 🎉 *Exploring Scratch Features* 01:39:04 📹 *Interactive Programming with Video Sensing* Introduction to *using Scratch for programming.* Creating a *program with synthesized speech.* Explaining the *concept of functions in programming.* Implementing conditional *behavior in Scratch.* 01:53:18 🔄 *Iterative Development in Scratch* 01:57:46 🎮 *Introduction to Programming Paradigm* 02:03:54 🧩 *More Complex Game Elements* 02:08:11 📊 *Evaluating Code Quality* 02:14:56 📄 *Structure of a Code Editor* 02:25:12 🔄 *Transition from Scratch to C* 03:02:01 🤖 *Simplifying Conditional Logic* 03:07:08 🧮 Exploring the structure of C code.* 03:09:30 🔄 Handling multiple conditions using "else if."* 03:10:28 🗃️ Handling a catch-all condition.* 03:11:36 🧩 Recap and review of C code.* 03:14:09 🔂 Code optimization by eliminating redundancy.* 03:14:25 🎯 Recap of coding concepts.* 03:14:34 🤔 Addressing questions and clarifications.* 03:50:56 🍪 *Break and Introduction to Mario ASCII Art* 03:53:54 🧱 *Printing a Column of Bricks* 03:55:18 🧱🧱🧱 *Printing a 3x3 Grid of Bricks* 03:56:01 🧱 *Discussing the idea of printing rows of bricks in a grid format.* 04:14:29 💡 *Creating Functions with Inputs* 04:49:23 🛠️ *Troubleshooting an error with get_string function,* 05:21:57 🐞 *Debugging with Breakpoints* 05:22:25 🐞 *Debugging in CS50,* 05:26:46 🦆 *Rubber Duck Debugging,* 05:55:23 🧠 *Introduction to arrays and for loops* 06:15:15 🖥️ *Manipulating Strings in C* 06:30:50 🐍 *Introduction to converting characters to uppercase in C* 06:35:12 📚 *Leveraging the ctype.h library for character manipulation* 06:42:34 🚀 *Command-line arguments in C programs* 06:48:22 🦆 *More fun with command-line arguments: Changing the "cow" to a "duck"* 06:49:21 🚀 *Exit Status and Error Codes* 06:50:29 🔍 *The Role of "int" in "main"* 07:24 🕒 *Understanding Algorithm Efficiency* 07:41:42 📚 *Introduction to creating a phone book in C* 07:43:33 🧮 *Introducing the concept of a custom data type* 07:59:00 🧐 *Sorting Algorithms Introduction* 08:08:00 🧼 *Bubble Sort* 08:18:10 🔄 *Bubble Sort Analysis* 08:27:04 ♻️ *Recursion and Recursive Functions* 08:57:04 🕰️ *Time Complexity of Merge Sort* 09:07:51 🧮 *Introduction to Hexadecimal and Base 16* 09:10:19 💡 *Understanding Hexadecimal Representation* 09:19:54 💡 *Getting the Address of a Variable* 09:44:01 🔍 *Introduction to Data Types and Strings in C* 10:03:55 💡 *Harnessing Pointer Arithmetic with Strings* 10:17:37 🧮 *Exploring string manipulation* 10:19:27 📝 *Copying strings and memory allocation* 10:47:25 💡 *Handling Garbage Values* 11:09:12 🔄 *Swapping values using pointers in C,* 11:13:00 🚫 *Memory limitations and potential issues in C,* 11:27:18 🧮 *Importance of Data Structures* 12:24:03 📜 *Adding Elements to Linked List* 12:34:00 📚 *Explanation of implementing a stack using linked lists,* 12:44:00 🔄 *Iterating over the linked list,* 12:51:00 🔗 *In this section, the main focus is on understanding the running time of various operations in linked lists.* 12:56:00 🌲 *This section introduces the concept of binary search trees (BSTs) as a way to achieve both binary search and dynamism.* 13:12:24 🌲 *Balanced binary search trees and algorithm complexity* 13:18:06 ⚖️ *Hashing and hash functions* 13:24:38 🧮 *Understanding Hash Tables and Memory Usage* 13:41:41 📚 *Introduction to Python* 13:56:53 📊 *Data Types in Python* 13:59:54 🖥️ *Implementing Spell Checker in Python* 14:11:12 🧑‍💻 *Face Recognition in Python* 14:19:13 🧮 *Variable manipulation and loops in Python* 14:26:53 🔄 *No need for a main function in Python* 14:33:41 🐍 *Integer overflow and big numbers in Python* 15:11:18 🖋️ *Python Printing Techniques* 15:26:12 🖥️ *Python: Accessing Command Line Arguments* 15:41:10 📚 *Introduction to Python Dictionaries and Their Use Cases* 15:43:28 🔄 *Swapping Values in Python* 15:47:12 📁 *Working with CSV Files in Python* 15:54:27 🔊 *Text-to-Speech Synthesis in Python* 15:57:36 🎓 *Conclusion and Introduction to SQL* 16:19:33 📊 *Improved Language Counting* 16:26:29 📈 *Sorting Data* 16:30:13 🔄 *Interactive User Input* 16:34:40 📊 *Introduction to Relational Databases* 16:36:06 🗃️ *Basic SQL Operations* 16:51:30 💼 *Introduction to SQL in Python* 17:08:10 🧩 *Database Design Considerations* 17:11:42 🔑 *Primary Keys and Foreign Keys* 17:26:27 📚 *Querying Relationships* 17:32:59 🌐 *Joining Multiple Tables* 17:43:37 🕵️ *Fuzzy Matching in SQL* 17:45:03 📈 *Creating a database index for faster searches* 18:01:29 🤖 *Introduction to the use of placeholders in SQL queries* 18:05:13 💼 *Preventing SQL injection attacks* 18:22:31 🌐 *Understanding the Basics of TCP/IP* 18:44:25 🌐 *HTTP as an Application-Level Protocol* 18:54:06 📨 *Viewing HTTP Request Headers* 19:05:27 🎉 *Prank at Harvard-Yale Football Game* 19:10:45 🌐 *Introduction to HTML and Web Technologies* 19:14:39 🖥️ *Running a Web Server with http-server* 19:15:36 🌐 *Accessing the Hosted Website* 19:16:46 🌐 *Understanding URL Structure* 19:17:39 🌐 *HTML Tag Hierarchy* 19:21:48 🌐 *HTML Elements and Hierarchy* 19:31:07 📚 *Introduction to HTML Tags* 19:32:29 📋 *Creating Lists in HTML* 19:47:43 🖥️ *HTML Meta Tags* 20:22:12 🧩 *Introduction to JavaScript* 20:23:35 📦 *JavaScript Variables* 20:25:14 🌐 *JavaScript in Web Development* 20:25:56 🖥️ *Client-Side JavaScript* 20:27:07 🔗 *HTML Form Creation* 20:29:56 🛠️ *Optimizing JavaScript Code* 20:45:47 📊 *Dynamic table sorting with JavaScript* 20:49:10 🌈 *Changing background color with JavaScript* 21:02:19 📂 *Folder Structure for Web Applications* 21:17:15 🌐 *Handling user input via URL parameters:* 21:35 🖼️ *Using Templates and Layouts* 21:48 📝 *Flask Web Development Basics* 22:03 🧩 *Template Layouts in Flask* 22:07:18 📋 *Storing user registration data in a dictionary* 22:10:18 📝 *Displaying user registrations on a webpage* 22:34:55 📊 *Displaying Registered Users* 23:36:23 🧠 *Overview of Computer Science Course* 23:51:38 💻 *Preparing for Post-CS50* 23:55:51 📚 *Introduction to Review Session* 23:56:19 🐍 *Python "Hello World" Question* 23:57:05 🌐 *DNS (Domain Name System) Question* 23:58:00 ⏰ *Merge Sort Runtime Question* 23:59:08 💻 *ARG C in C Programming Question* 24:00:19 📂 *File Opening Function in C Question* 24:08:45 🍽️ *Valid Way to Print Exclamation Point Question* 24:10:23 🖥️ *Compiling Steps Question* 24:11:02 🤯 *Surprise at the Beginning of the Halloween Lecture Question* 24:13:20 🌎 *Unicode and Emoji Introduction* 24:14:28 🍣 *Representation of Japanese Foods in Emoji* 24:16:06 🌐 *Universal Appeal of Dumplings Discussion* 24:17:00 🍣 *Introduction to Jennifer 8 Lee's Talk* 24:20:33 😊 *Evolution of Emoji Discussion* 24:22:13 🌟 *Unicode Consortium and Emoji* 24:25:20 🍔 *Representation of Food in Emoji* 24:27:17 🙏 *Importance of Inclusivity in Emoji* 24:37:32 📚 *Introduction to the Next Section* 24:39:20 💾 *Memory Hierarchy* 24:40:25 💿 *Storage Devices* 24:41:31 🕒 *CPU Clock Speed* 24:45:15 💻 *System Architecture Quiz* 24:48:33 🔄 *Algorithm Efficiency* 24:56:00 📖 *Recommended Books* 24:57:52 🎉 *Farewell and Good Luck* 23:58:00 🔄 *Merge Sort Algorithm Analysis* 24:00:19 👾 *The Duck Debugger* 24:03:00 🤝 *How Strings Length is Computed in C* 24:10:09 🚀 *Arrow Operator in C* 24:12:54 🍣 *Missing Dumpling Emoji* 24:16:21 🤝 *Involvement with Unicode Consortium* 24:29:02 💡 *Encoding Characters and Code Points* 24:33:07 🌐 *Depiction of Race and Nationality in Emoji* 24:33:35 🎨 *Evolution of Emoji Design* 24:36:30 👩‍🎨 *Contributions to Emoji* 24:53:46 🔁 *Emoji Directionality* 24:55:36 🎉 *Future of Emojis* 25:03:07 🤖 *Course Conclusion* 25:09:54 🔐 *Password Choices* 25:10:23 🔐 *Password Security* 25:12:26 🔓 *Cracking a 4-Digit Passcode* 25:28:22 🔒 *Lockout Mechanism*

[@Quran-Clips1445]

thank you so much

[@jamesmichaelcabrera9613]

Wow 😅

[@alexandruvalentin2035]

Thank you kindly you absolute mad lad

[@badwolf1259]

thank you

[@siiuuuu77777]

🎉✊

[@IgorKuts]

I am literally speechless. This is not just teaching, this is art. Those students are blessed by having such an opportunity.

[@raav2878]

those students worked their ass off to get into Harvard and their parents paid a ton of money. make no mistake. this is marketing for Harvard university.

[@ramonguerra745]

We are blessed to have such an opportunity!

[@IgorKuts]

​@@raav2878 "While it may seem a bit harsh, it is undeniably true. Nonetheless, the effort and money invested were well spent. The mere difficulty or expense of something does not always guarantee the highest quality."

[@trurocker03]

Well for the price of Harvard you should expect nothing more than world class professors like this.

[@FrazerHatyai]

the white and chinese ones did. @@raav2878

[@RetroWasNotAavailable]

Really shows how important it is to have good lecturers for learning. Whoever made the subtitles deserves love and support.

[@HusseinAbdi-lf5oc]

Is it the full whole computer science course

[@VladdyHell]

Yeah KZbin auto-subtitle deserves love and support🤣🤣🤣

[@RetroWasNotAavailable]

@@VladdyHell yeah i know 😂, free likes dude!

[@alejandrocamilo7456]

He speaks very fast so I had to adjust the speed at 0.75

[@AznInvasion85]

The subtitles and the transcript are on the website

[@thelife5628]

5:00:11 Compiling converts C code into assembly code. 5:01:53 AMD CPUs understand Assembly Language for efficient code execution 5:05:45 The code is stored on a virtual hard drive in the cloud. 5:07:54 The purpose of a library is to make it easier to use and reuse code that's already been written. 5:11:53 Code compiled into zeros and ones is not necessarily predictable, making decompiling challenging. 5:13:34 Debugging code is a lifelong skill and there are tools and techniques available to make it easier. 5:16:57 Debugging using printf statements 5:18:42 Using printf as a diagnostic tool in programming 5:22:09 Using breakpoints in debug mode to step through code 5:23:56 The debugger in CS50 shows variables and allows stepping through code 5:27:18 Using a panel to display changing values instead of print statement 5:29:07 The cs50 library prompts the user for a negative integer and stores the value in n. 5:32:52 Exploring the behavior of a 'do-while' loop in the program. 5:34:38 Using a debugger can help in finding bugs in code 5:38:11 Data types represent different types of data with a specific number of bits allocated to them. 5:39:58 Data in computers is represented using bits and bytes. 5:43:27 Memory in a computer is like a canvas for storing information in units of bytes or 8 bits. 5:45:11 Computing the average of three values using C 5:48:42 The video discusses the concept of memory and storing data. 5:50:33 Declare an array in C to store three integer values 5:54:26 Using loops to avoid repetitive code and improve code design. 5:56:21 Memory in computers is contiguous, and arrays can be passed as arguments in code. 5:59:58 Declare a constant variable to avoid hardcoding and easily reuse values. 6:02:01 Taking the average of a variable number of scores using a loop. 6:06:01 In C, you must remember the length of an array yourself. 6:07:58 In C, you cannot determine the size of an array when it is passed into a function. 6:11:31 A string is just an array of characters in memory. 6:13:24 Strings in memory take up one more byte than the characters typed by the programmer 6:17:12 Understanding operations on strings in computer science. 6:19:12 Strings in C are treated differently and have special implementations 6:22:59 Manipulating strings in arrays using new syntax 6:25:11 Calculate the length of a string in C 6:28:54 Introduce string manipulation and library functions in C 6:30:56 Iterate through each character in a given string, check if it is lowercase, and convert it to uppercase. 6:34:53 Using libraries in programming to solve common problems efficiently 6:36:42 Implement a program that's correct but better designed with fewer lines of code and lower probability of mistakes. 6:40:40 Introducing command-line arguments in the program 6:42:40 argc stands for argument count and is used to determine the length of the array of words typed at the prompt. 6:46:44 Command line arguments are used to modify the behavior of a program. 6:48:34 Command line arguments and exit status in coding 6:52:22 You can use the command 'Echo $?' to see the exit status of your program. 6:54:17 Cryptography is the art and science of encrypting information. 6:57:50 Encryption and decryption process explained 7:01:19 Efficiency of algorithms and its impact on solving problems 7:04:40 Searching algorithms and memory storage in computers 7:06:20 Executing the linear search algorithm to find the hidden 50 in the lockers 7:10:26 Using bracket notation, Jackson can treat the set of lockers as an array 7:12:06 Using binary search algorithm to find a number in an array 7:15:44 Divide and conquer approach for searching in an array 7:17:30 Binary search is more efficient than linear search 7:20:54 Algorithms perform similarly for large input sizes 7:22:39 Linear search has a time complexity of O(n) and binary search has a time complexity of O(log n). 7:26:21 Big O, Omega, and Theta allow computer scientists to analyze algorithm efficiency. 7:28:04 Translate the discussed ideas to actual code using arrays 7:31:50 Implementation of linear search in C using an array of numbers. 7:33:44 String comparison in C requires using a function called strcmp instead of == operator. 7:37:50 Avoid touching memory that shouldn't be accessed 7:39:40 Returning zero in main signifies code execution is successful 7:43:25 Using a 2D array to store names and numbers is a cleaner approach than combining them into the same array. 7:45:20 Code successfully searches for phone numbers in a phone book. 7:49:16 Defining a new data type called person using struct keyword 7:51:08 Creating a structure to store person's information 7:54:51 Read and update information dynamically from a file 7:56:50 C cannot set default values in struct, unlike more modern languages like Python and Java. 8:00:49 Sorting volunteers using selection sort algorithm 8:02:34 Using selection sort to sort a list of numbers 8:05:56 Bubble sort is a different approach to sorting that focuses on smaller problems. 8:07:34 Bubble sort algorithm to solve sorting problems 8:11:25 Counting the number of comparisons is a global unit of measure to analyze algorithms. 8:13:14 Number of comparisons to find the smallest element decreases by 1 for each iteration. 8:16:57 Selection sort takes N^2 steps in worst case and N^2 steps in best case 8:18:52 Iterate through the array from 0 to n minus 2 to avoid going beyond array boundaries. 8:22:30 Bubble sort has a short-circuit detail helpful for already sorted data 8:24:27 Sorting algorithms like selection sort and bubble sort have a redundant comparison process that results in slow performance for large numbers 8:28:14 Recursion allows calling a function on a smaller version of the problem until no more problems to solve. 8:30:05 Recursive search algorithm for a phone book 8:33:52 Implementing a pyramid drawing function using recursion. 8:35:49 Creating a pyramid recursively 8:39:33 The base case is important to prevent the code from running forever. 8:41:20 Recursion can be used with return values. 8:45:07 Merging two sorted halves 8:46:51 Merge sort requires additional memory for implementation 8:50:24 Sorting the left half and right half of the original input separately 8:52:19 Merging and sorting the left and right halves of the given list 8:56:09 The running time of merge sort is O(n log n) and it is better than bubble sort and selection sort. 8:57:56 Merge sort is generally preferred for sorting as it is faster. 9:03:45 Understanding computer memory helps in representing and creating interesting things 9:05:26 RGB color system: Red, Green, Blue 9:08:59 Hexadecimal is a base-16 system used to represent numbers beyond 0-9. 9:10:53 Heximal (hexadecimal) is a number system that uses 16 symbols to count. It is useful for various applications. 9:14:48 Hexadecimal is a base system used in computers to represent information. 9:16:35 Hexadecimal is commonly used to describe memory locations in computer systems and software. 9:20:11 Conceptually, the programmer knows that the number 50 is assigned to the symbol n in the computer's memory. 9:21:51 C language has operators to get the address of a variable and go to a specific address in memory. 9:25:30 A pointer is a variable that contains the address of a value. 9:27:23 The video explains the concept of pointers in C programming. 9:30:59 The code assigns the value of 'n' to variable 'p' using the address of 'n'. 9:32:42 Pointers are variables that point to something else 9:36:19 Arrays and pointers have a relationship, but are technically different. 9:38:07 Strings in programming are special as they store multiple characters and have a null character at the end. 9:41:42 String in C is actually a Char star 9:43:30 Defining data types in C using type def 9:47:13 Pointers in C are declared using the star symbol and can be dereferenced using the star symbol. 9:49:00 Printing the address of a string using the %p format specifier 9:52:40 The 'percent s' is used in printf to print the characters in a string. 9:54:39 The video discusses the concept of addresses in C programming. 9:58:19 Printing characters from a string using pointers

[@ShmurdaaaA]

Hey I’m just wondering is this C# he teaches

[@theprofessional2884]

@@ShmurdaaaA i didn't watch the whole video so i only saw him teaching in C. But if you're asking if C and C# are the same, the answer is no, they're completely different languages. C is more similar to C++

[@ShmurdaaaA]

@@theprofessional2884 thank you for that was looking to know looking for a C sharpe one

[@ez7125]

Save

[@mauishingles4257]

thanks for spoiling it bro

[@thelife5628]

10:00:08 Pointer arithmetic allows performing operations on pointers to manipulate memory addresses. 10:03:24 The power and danger of C programming and solving various segfault errors 10:05:08 Printing substrings of a string using printf 10:08:45 The program compares two strings and determines if they are the same or different. 10:10:30 Comparing strings in C involves comparing the memory addresses 10:14:06 String comparison in programming is special and treated differently from other data types. 10:16:13 Explains the concept of address and how it is used in comparing characters of strings. 10:19:55 Line 12 capitalizes the first letter of T 10:21:48 Python and other languages have benefits 10:25:30 Managing memory using malloc and free 10:27:05 Copying a string to another variable using pointers and memory allocation. 10:30:47 Iterating over and copying the characters in a string. 10:32:48 Avoid calling a function repeatedly inside your condition in a loop. 10:36:31 Use null to signal errors in coding 10:38:13 Always free memory allocated using malloc 10:41:46 Introducing the program valgrind to find memory errors in code execution 10:43:33 Bug in memory allocation and writing 10:47:07 Not initializing values in an array in C can lead to unpredictable output. 10:48:50 Garbage values in computer memory can cause errors in programs. 10:52:19 Understanding pointers and how they work 10:54:21 Manipulating memory with pointers. 10:58:09 Swapping two values using a temporary variable 10:59:51 Passing arguments by value in C does not allow swapping of values 11:03:25 Memory management in computer programs 11:05:07 Understanding memory allocation and deallocation in programs. 11:08:37 You can change the value of a variable by following memory addresses and swapping the values. 11:10:14 Passing addresses instead of integers for swap function 11:13:46 Buffer overflows can occur due to logical bugs in code 11:15:28 scanf can change the value of X by reference using Ampersand 11:19:08 Not initializing a pointer can lead to reading/writing into garbage memory locations. 11:20:59 Handling variable length inputs in C programming. 11:24:09 Introduction to reading and writing files in C 11:27:11 This week we will focus on data structures and abstract data types. 11:31:08 FIFO and LIFO are two different ways of adding and removing items from a queue or stack. 11:32:47 Storing emails and sweaters using a stack 11:36:29 The main limitation of this design is that it can only hold a finite number of items. 11:38:16 Jack learns to use a queue to manage his clothes 11:41:49 Moving a string to a new chunk of memory to add a number 11:43:27 Growing the array in this way can lead to inefficiency 11:47:07 Allocating memory dynamically for an array in C programming. 11:48:53 Using a pointer instead of an array for a list increases dynamism. 11:52:40 Copying bytes from old array to new array, allocating and freeing memory in C programming 11:54:31 Implementing inefficient allocation and population of a new array with a fourth value. 11:58:35 The function realloc simplifies the process of reallocating memory in C. 12:00:30 The use of realloc in C allows for dynamic memory allocation and copying without the need for explicit for loops. 12:04:32 Arrays and memory manipulation in computer science 12:06:20 Struct in C allows us to create our own structure in memory. 12:09:50 Creating a linked list with random memory positions 12:11:47 Use a sentinel value as a special signal for an invalid address 12:15:35 To enable backward traversal in a linked list, we can use a doubly linked list or make the list circular. 12:17:25 Using pointers in C to create self-referential structures 12:21:11 Using linked lists in place of arrays increases memory usage and eliminates the ability to index elements. 12:22:54 Binary search algorithm cannot be used when the data is not sequentially stored in memory. 12:26:10 Executing the provided code assigns a valid pointer to variable n. 12:27:53 Syntax for dereferencing a pointer and accessing a structure using arrow notation 12:31:22 Memory leak due to orphaned node 12:33:17 Implementing a stack using a linked list 12:36:52 Implementing a linked list of size zero and taking command line arguments 12:38:51 Converting command line arguments to integers using atoi. 12:42:28 Printing each number in a linked list 12:44:14 Iterating over a linked list using pointers and the null value 12:48:06 To avoid segmentation faults, use a temporary pointer for swapping and freeing memory. 12:49:54 Understanding the usage of while loops and for loops in iterating over nodes in a linked list. 12:53:23 Appending values at the end of a linked list increases the running time to O(n). 12:55:02 Maintaining a sorted list in a linked list 12:58:31 Binary search trees are structured like family trees and have special properties for binary search. 13:00:24 Using a two-dimensional approach for array layout and introducing nodes and pointers to connect them 13:03:56 Implementing binary search using a two-dimensional structure 13:05:45 Recursion is a beautiful technique for dealing with two-dimensional structures. 13:09:21 Not necessary to have pointers in both directions, but it can improve efficiency. 13:11:10 Implementing a binary search tree without balancing can result in an unbalanced tree with a height of N instead of log base 2 of N 13:14:39 Hashing is a final building block to achieve constant time lookup. 13:16:26 Sorting a deck of cards using bucketization and hashing. 13:20:16 Using linked lists improves the efficiency of contact lookup in a contact card representation 13:22:07 Hash tables offer efficient search time in constant time 13:25:49 Representation of nodes in the tree 13:27:35 Hash tables allow for constant time indexing and searching. 13:31:32 Tries are a data structure that combines aspects of arrays and hash tables. 13:33:21 Finding someone in a trie data structure takes a constant number of steps, regardless of the number of names in the data structure. 13:36:58 The try data structure is used to efficiently store and retrieve data. 13:39:00 Data structures are everywhere in the real world 13:44:03 Transition from Scratch to Python 13:45:46 Python eliminates the need for compiling code and allows program to be interpreted directly 13:49:05 Running python hello.py will print 'hello world' on the terminal. 13:50:50 In Python, the syntax for declaring variables and printing has changed compared to C. 13:54:22 Python supports format strings or F strings for automatic value substitution. 13:56:16 Python printing with curly braces 13:59:52 Implementing a spell checker in Python instead of C 14:01:38 Using a set in Python can be used as a dictionary for spellchecking words. 14:05:15 The C version of spell checker compiled faster than the Python version. 14:07:10 Using a more modern and user-friendly language like Python comes with a trade-off of potential performance loss. 14:10:46 Face recognition software can analyze and detect multiple faces, but can be trained to recognize specific faces. 14:12:44 Software can identify a human face by analyzing patterns of pixels. 14:16:21 Python has simplified the syntax for conditionals and introduced the 'elif' keyword 14:18:07 In Python, you can create a variable and set its initial value without specifying the type or using a semicolon. 14:21:33 Using the range function in Python is more efficient than hardcoding a list of numbers. 14:23:16 Infinite loops can be implemented using a 'while true' statement in C and a 'while True' statement in Python. 14:26:49 The default indentation in a Python file is left indented, and code is executed top to bottom, left to right 14:28:44 Python has a built-in function called 'int' to convert a string to an integer. 14:32:35 Python has solutions for floating point precision issues and integer overflow 14:34:31 Comparing values in C and Python 14:38:26 Explaining the usage of single quotes and double quotes in Python 14:40:17 In Python, you can use the 'in' keyword to search a list and it will return True if the value is found and False if not. 14:44:12 Python strings have built-in methods that can modify their values. 14:46:16 Strings in Python are immutable and cannot be changed directly 14:49:51 Implementing functions in Python using the 'def' keyword 14:51:34 Troubleshooting Python name errors 14:55:15 Code execution order in Python 14:57:04 Introducing Python's functionality to print a vertical column of bricks in the Mario game

[@gnomewarlord7128]

Bro’s a saint

[@aps.stellar]

Yup ,I agree

[@sidhu704]

I graduated from my undergrad in CS at a uni in the UK back in 2019, decided to watch this since my field of work briefly shifted post uni, but now coming back to software dev thought about checking this out, I'm only 2 hours into this course and it's already miles and miles better than what I went through on my course, almost feels like I wasted money, there were useful bits ofc, but this is just highly engaging and so well structured. So glad this is available for free!!!!

[@LordBigOoof]

What uni

[@DailyShit.]

If universities were actually this engaging people would actually care and go regularly

[@migueljaques6780]

@@DailyShit.if they would get paid they would…

[@aoi-arashi]

@@DailyShit. Looks pretty empty there sometimes tbf

[@turdwarbler]

Hmmmm, if you were a Computer Science graduate in 2019, and you are going back to this, then there was something seriously wrong wth your computer science course, either that or you didint attend lectures. You should be so far beyond what he is talking about. there is just no comparison. Before anybody has a go, I do speak from experience, as I am a computer science graduate and in the past I have taught C & Advanced C for over 10 years.

[@MC75448]

The light bulbs on the edge of the stage spell a different word in binary for each class. I've never loved a class more. David makes learning effortless.

[@Awoken369]

He broke things down and explained topics so well. I'm thankful that this was provided for free and thankful to those who uploaded this moment in history.

[@richardmasters2045]

I’m crying right now because I was denied a college education after being shot and disabled and was not able to afford to get the education of such caliber. David is an amazing professor and I am grateful to be able to watch this awesome CS50 course.

[@twocauses]

For what it's worth, I don't know you and you don't know me, but just from one stranger to another somewhere out there even though I have no idea where you're from or anything about your life, here's a general tip: I can't say how much information you can learn for free out there, and I wish I could just make you believe me somehow, but you can honestly find ANY information that you could get ina college/university simply on KZbin. This video itself is just sheer proof of that. So if you think this is good, just imagine what you would be able to do (learn) if you could just start searching correctly on that search bar above all this, and on Google. A very smart programmer/hacker once said: "The only way to learn programming is to not only watch tutorials, but just pick a project and start a project and start making it. There is no other way to learn how to code." I know he said something like that, maybe not exactly but the point is still the same. You got this man. Sorry, I just felt like I couldn't just be another person just scrolling past and ignore your comment as it touched my heart. Good luck dude.

[@kgb_1520]

ha caliber.

[@proloycodes]

why would colleges reject disabled people tho?

[@sensor]

@@proloycodes I think the problem is that he needed to use the money reserved for college for the injury.

[@ali-g]

@@sensor american problems

[@realbenedictik]

This harvard lecturer has so much passion impacting knowledge. 20 mins in and I've learnt quite a lot.

[@english-learningadventure4795]

That reminded me that sometimes the way the teacher does his/her job can considerably impact a student 's life and the way the students see the subject.

[@etheman80]

love how you can fast forward to any point, and the energy level never decreases

[@thewiseowl8804]

That is what makes him obnoxious to me: he never stops and takes a breath. This entire video is worthless. I can’t learn when someone is yelling continuously.

[@Notsosarcastic_02]

26 hours of full course and no ads ? You people are doing god's work !! Harvard CS course for free that too without any ads !

[@overanalyzings]

Do y’all not use Adblock? I haven’t seen a KZbin ad in years. I guess if you watch on a phone it’s harder which I understand. BUT PEOPLE: IF YOU USE KZbin ON A COMPUTER PLEASE USE ADBLOCK.

[@sebastianpedraza4481]

I have ads :(

[@samsebin7895]

@@sebastianpedraza4481 use adblocker bro if you are using laptop

[@AyushiRai04]

A huge huge huge respect to you guys! Wow! Thanks for compiling all the information under one place

[@sylviasokeschroter]

Sehr Gute Videos Danke

[@fctinmaz]

every computer science professor around the world should watch this. amazing lecture!

[@fagan1031]

Goodness yes !!my computer science class was a snooze fest at 8am ! University of Miami was more about teaching us how to turn it on and cop c copy v and the class / professor was as interesting as watching grass grow!! If I knew professors looked like this dude I would have attended Harvard ! What a gift this is!!

[@dellenga]

I can`t believe Harvard just dropped a 24h course for free for us

[@edwardselirah4764]

The professor makes the course so nice and enjoyable...the students are blessed.

[@Felttipfuzzywuzzyflyguy]

Was just legit watching the previous version and saw this upload 😅 This is awesome, thank you so much for making this available for free!

[@dreamisover9813]

Excellent! Those are some of the most high quality courses out there, thanks

[@user-tt2po5wg7n]

The professor makes the course so nice and enjoyable...the students are blessed.. every computer science professor around the world should watch this. amazing lecture!.

[@davmaga1214]

🎯 Key Takeaways for quick navigation: 00:00 🎓 *Introduction to CS50* 16:44 🎉 *CS50 Events and Community Engagement* 17:27 🔍 *Introduction to Problem Solving* 26:30 🎭 *Binary Representation Demonstration* 34:52 🧠 *ASCII representation of letters* 37:07 🌐 *Unicode and character representation* 40:31 🎨 *Unicode expansion and use of multiple bytes* 46:23 🌈 *Advanced Emoji representation* 53:01 🎥 *Basics of Video Representation* 56:35 📦 *Abstraction and Algorithms* 57:48 📖 *Searching Algorithms - Phone Book Example* 01:05:03 📝 *Pseudocode and Programming Concepts* 01:08:43 🚀 *Introduction to Scratch programming* 01:14:54 🖥️ *Writing the first Scratch program* 01:20:56 🤖 *Interactive Scratch program with user input* 01:24:52 🚀 *Scratch Programming Basics* 01:27:10 🐱 *Scratch Sounds and Duplicate Blocks* 01:28:39 🔄 *Refactoring with Loops* 01:31:27 🧩 *Creating Custom Blocks* 01:39:32 📷 *Video Sensing for Interaction* 01:43:27 🕹️ *Implementation Details of Scratch Game* 01:45:56 🔄 *Iterative Development Process* 02:06:32 🎮 *Programming Game Features* 02:11:12 🛠️ *Evaluating Code Quality* 02:19:25 🛠️ *Compiling and running C programs in VS Code* 02:23:48 🎨 *Syntax highlighting and understanding C code structure* 02:35:48 📚 *Including Header Files in C Programs* 02:41:49 📚 *Utilizing cs50.h Library* 02:54:19 🎉 *Enhancing `printf`* 02:57:19 🧩 *Data Types in C* 02:58:45 ⏸️ *Break Announcement* 03:02:55 🤔 *Simplifying Conditionals* 03:07:08 🔄 *Logical Operations and Conditions in C* 03:13:41 🤝 *Agreement System in C* 03:19:47 ♦️ *Improving Case Handling in C* 03:22:23 🔁 *Introducing Loops in C* 03:38:48 🔁 *Infinite Loop in C (Forever Block)* 03:41:06 ⚙️ *Handling Infinite Loops and Using Ctrl+C* 03:43:41 📡 *Basic Command Line Commands in Linux* 03:50:56 🕹️ *Solving General Programming Problems in C* 03:56:30 🧱 *Printing 3x3 Grids in C* 03:57:09 🔄 *Loop structure and variable naming* 04:08:24 📝 *Coding Style and Comments* 04:10:38 🧩 *Abstraction and Pseudocode* 04:13:35 📝 *Functions and Abstractions* 04:20:31 🕹️ *Integer Overflow and Longs* 04:31:08 🧮 *Floating Point Precision in C* 04:36:05 🌐 *Goals of CS50 - Understanding Computing Bottom-Up* 04:39:53 🔐 *Introduction to Cryptography and Cipher Text* 04:43:50 🖥️ *Manual Compilation with Clang and Custom Output* 04:47:16 🔄 *Compiling Code with Dynamic Input* 04:49:51 🛠️ *Compilation Process Overview* 05:08:22 🌐 *Compilation Steps Breakdown* 05:14:28 🐜 *Origin of the Term "Bug"* 05:24:00 🛠️ *Debugging with Debug50* 05:38:24 📊 *Data Types and Representation* 05:49:45 🔄 *Improving Code Design with Arrays* 05:57:26 🧮 *Function "average" Implementation:* 06:00:11 🔄 *Improving Main Function:* 06:06:20 📏 *Array Size in C:* 06:07:31 🎭 *Passing Array Length as a Parameter:* 06:10:55 📝 *Introduction to Strings in C:* 06:20:41 🧩 *Working with Arrays of Strings* 06:32:54 🧮 *Char manipulation and ASCII conversion* 06:35:27 📚 *Leveraging ctype.h Library for Case Conversion* 06:49:06 🚪 *Exit Status in C* 06:50:42 🔍 *Understanding C Programming* 06:59:00 🛡️ *Using Exit Status in C Programs* 07:09:47 🔄 *Array Introduction and Pseudo Code* 07:13:18 🧩 *Binary Search Demonstration* 07:27:38 📊 *Examples of Big Theta* 07:44:02 📚 *Introduction to the Phone Book Example* 07:55:18 🧱 *Implementation of a Struct in the Phone Book* 07:58:27 🔄 *Break and Recap* 07:59:11 🤔 *Considerations for Sorting Data* 08:01:51 🌐 *In-Class Sorting Activity* 08:06:51 🔄 *Bubble Sort Overview* 08:11:38 📊 *Analysis: Selection Sort* 08:18:22 📊 *Analysis: Bubble Sort* 08:20:01 🔄 *Bubble Sort Pseudo Code Analysis* 08:23:39 🌐 *Visualization of Sorting Algorithms* 08:28:56 🔄 *Recursive Elements in Algorithms* 08:36:38 🔄 *Recursive call and Base Case* 08:38:41 🔄 *Recursive Draw Function* 08:53:14 🔄 *Merge Sort Algorithm Explanation* 08:54:48 🧠 *Divide and Conquer in Merge Sort* 08:55:55 📉 *Time Complexity of Merge Sort* 08:58:01 🤔 *Space Complexity Considerations in Merge Sort* 08:58:15 🔄 *Tradeoffs in Sorting Algorithms* 09:00:16 🎓 *Conclusion of CS50 Course* 09:12:36 🧮 *Hexadecimal Representation* 09:14:40 🤔 *Understanding Hexadecimal* 09:15:46 🌐 *Hexadecimal in Computer Systems* 09:17:24 🕵️ *Hexadecimal in Memory Addresses* 09:19:28 🔄 *Exploring Memory with Pointers* 09:27:43 ⚙️ *Using Pointers* 09:29:32 🚀 *Pointers in C* 09:30:42 🔍 *Pointers and Data Types* 09:34:18 📬 *Memory Addresses Analogy* 09:35:28 🗺️ *Pointers Pointing at Values* 09:36:45 🔄 *Arrays vs. Pointers* 09:39:18 🧵 *Strings as Pointers* 09:42:25 🤯 *Unveiling String's True Nature* 09:49:34 📝 *Working with Strings and Addresses in C* 09:53:42 🤔 *Why `%s` for Strings in `printf`* 10:04:09 📜 *Exploring Strings with Pointer Arithmetic* 10:06:39 🔄 *Utilizing Pointer Arithmetic for Strings* 10:10:03 🧐 *String Comparison with `strcmp`* 10:17:50 🕵️‍♂️ *Examining Memory Addresses* 10:20:20 🔄 *String Copying Basics* 10:34:22 🔄 *Leveraging Standard Library Functions* 10:37:23 🧠 *Memory Management in C* 10:39:34 🗣️ *Understanding `free` in C* 10:43:18 🛠️ *Using Valgrind for Memory Debugging* 10:49:03 🚫 *Avoiding Garbage Values* 10:50:38 🧨 *Pitfalls with Pointers* 10:54:04 🧠 *Understanding pointer assignment* 10:58:13 🔄 *Swapping values using a temporary variable* 11:01:26 💡 *Understanding memory segments in C* 11:10:37 🔄 *Pointers and Ampersands in C* 11:14:24 💡 *User Input Handling in C* 11:28:35 🧠 *Introduction to Abstract Data Types* 11:38:22 🎭 *A Creative Explanation of Queues and Stacks* 11:40:28 🧱 *Implementing Queues and Stacks with Arrays* 11:43:04 🔄 *Dynamic Solutions for Resizing Arrays* 11:46:12 🖥️ *Transition to Dynamic Memory Allocation* 11:49:50 🔄 *Dynamic Memory Allocation in Action* 11:53:15 🔄 *Realloc Function for Array Expansion* 11:59:50 ❓ *Questions and Clarifications* 12:03:04 🔄 *Linked Lists Introduction* 12:06:16 🧠 *Building Data Structures with Memory Allocation* 12:07:35 🔗 *Linked List Implementation in Code* 12:24:03 📝 *Translating Concepts to Code: Building a Linked List* 12:54:05 🔄 *Linked List Insertion Overview* 12:55:15 🔄 *Inserting into a Sorted Linked List* 12:58:12 🌳 *Introduction to Binary Search Trees* 13:11:00 🌲 *Hash Tables and Binary Search Trees* 13:21:16 ⚖️ *Trade-offs in Hash Tables* 13:26:42 📦 *Implementation of Hash Tables* 13:28:17 📚 *Memory Management in Arrays* 13:30:54 🌲 *Introduction to Tries* 13:54:08 🧾 *Introduction to f-strings for formatted strings* 14:04:21 🧠 *Trade-offs in Programming Languages* 14:14:06 ⌨️ *CS50 Library in Python* 14:15:29 🔄 *Python Conditionals* 14:18:06 🔢 *Python Variables and Incrementing* 14:19:54 🔁 *Python Loops* 14:21:02 📚 *Efficient List Generation with Python's Range* 14:23:22 🔄 *Infinite Loops in Python* 14:26:41 🔧 *Removing Training Wheels in Python* 14:39:07 📚 *Lists and 'in' Keyword* 14:43:00 🐍 *Object-Oriented Programming in Python* 14:49:29 🔁 *Introduction to Loops in Python* 14:57:13 🔄 *Introduction to loops in Python* 15:00:50 🔄 *Pythonic approach to input validation* 15:11:18 📜 *Printing horizontal characters in Python* 15:12:00 💻 *Printing in Python with Named Arguments* 15:15:02 🔄 *Using the Star Operator for String Multiplication* 15:18:02 📊 *Working with Lists in Python* 15:26:12 🎛️ *Command Line Arguments with sys.argv* 15:28:46 🔄 *Iterating Over Command Line Arguments* 15:31:18 🚪 *Exiting Programs and Error Handling* 15:36:05 🔄 *Pythonic Way of Searching in Lists* 15:43:41 🔄 *String Comparison in Python* 15:48:20 📂 *Working with CSV Files in Python* 16:00:04 📊 *Introduction to SQL* 16:05:08 🐍 *Working with CSV Files in Python* 16:36:18 🔄 *SQL Commands: Create Table and Basic Structure* 16:46:17 📊 *Using COUNT() and DISTINCT* 16:54:46 🔄 *Inserting Data into SQL Table* 17:00:15 🚫 *SQL DELETE Command and its Destructive Nature* 17:06:04 🗄️ *Overview of IMDb Database Schema and Relationships* 17:11:28 🔄 *One-to-Many and Many-to-Many Relationships in Databases* 17:14:29 🛢️ *Understanding Database Constraints* 17:27:44 👤 *Retrieving Data for a Specific Person* 17:31:50 🎬 *Introduction to Dynamic Queries* 17:33:15 🔄 *Joining Tables in SQL* 17:37:18 ⚖️ *Combining Data: Joining Shows and Ratings* 17:38:27 🌐 *Advanced Queries and Problem Solving* 17:49:04 🕵️ *Database Indexing Basics* 17:54:45 📊 *Retrieving Data from SQL Database in Python* 18:02:38 🏁 *Challenges in Handling Race Conditions in SQL* 18:11:15 🔒 *Preventing SQL Injection* 18:26:47 🔄 *Data Routing with TCP/IP* 18:34:11 📧 *TCP (Transmission Control Protocol) and Port Numbers* 18:39:21 🔍 *DNS (Domain Name System)* 18:43:02 🌐 *HTTP (Hypertext Transfer Protocol)* 18:48:48 📡 *URL Scheme or Protocol* 19:02:26 🌐 *HTTP Basics and Status Codes* 19:05:14 🎭 *Fun with HTTP: Yale Prank Story* 19:06:52 🕸️ *Transition to Web Development* 19:26:15 📜 *Working with Paragraphs* 19:31:35 📚 *HTML Headings* 19:35:16 📊 *HTML Tables* 19:36:49 🖼️ *Image Tag in HTML* 19:51:56 🔍 *Creating a Search Form in HTML*

[@ojasdhamapurkar2191]

Salute to you, guys. You are real heroes for novice and expert programmers. ❤️

[@ComputerAdventures]

CS50 has helped me a lot. Thank you for compiling this and also thanks to David Malan for providing these useful lectures to the public!

[@tjmns]

will be binge watching all of this over the next few weeks thanks !!!

[@AnshParmar1]

for me 10:00:08 Pointer arithmetic allows performing operations on pointers to manipulate memory addresses. 10:03:24 The power and danger of C programming and solving various segfault errors 10:05:08 Printing substrings of a string using printf 10:08:45 The program compares two strings and determines if they are the same or different. 10:10:30 Comparing strings in C involves comparing the memory addresses 10:14:06 String comparison in programming is special and treated differently from other data types. 10:16:13 Explains the concept of address and how it is used in comparing characters of strings. 10:19:55 Line 12 capitalizes the first letter of T 10:21:48 Python and other languages have benefits 10:25:30 Managing memory using malloc and free 10:27:05 Copying a string to another variable using pointers and memory allocation. 10:30:47 Iterating over and copying the characters in a string. 10:32:48 Avoid calling a function repeatedly inside your condition in a loop. 10:36:31 Use null to signal errors in coding 10:38:13 Always free memory allocated using malloc 10:41:46 Introducing the program valgrind to find memory errors in code execution 10:43:33 Bug in memory allocation and writing 10:47:07 Not initializing values in an array in C can lead to unpredictable output. 10:48:50 Garbage values in computer memory can cause errors in programs. 10:52:19 Understanding pointers and how they work 10:54:21 Manipulating memory with pointers. 10:58:09 Swapping two values using a temporary variable 10:59:51 Passing arguments by value in C does not allow swapping of values 11:03:25 Memory management in computer programs 11:05:07 Understanding memory allocation and deallocation in programs. 11:08:37 You can change the value of a variable by following memory addresses and swapping the values. 11:10:14 Passing addresses instead of integers for swap function 11:13:46 Buffer overflows can occur due to logical bugs in code 11:15:28 scanf can change the value of X by reference using Ampersand 11:19:08 Not initializing a pointer can lead to reading/writing into garbage memory locations. 11:20:59 Handling variable length inputs in C programming. 11:24:09 Introduction to reading and writing files in C 11:27:11 This week we will focus on data structures and abstract data types. 11:31:08 FIFO and LIFO are two different ways of adding and removing items from a queue or stack. 11:32:47 Storing emails and sweaters using a stack 11:36:29 The main limitation of this design is that it can only hold a finite number of items. 11:38:16 Jack learns to use a queue to manage his clothes 11:41:49 Moving a string to a new chunk of memory to add a number 11:43:27 Growing the array in this way can lead to inefficiency 11:47:07 Allocating memory dynamically for an array in C programming. 11:48:53 Using a pointer instead of an array for a list increases dynamism. 11:52:40 Copying bytes from old array to new array, allocating and freeing memory in C programming 11:54:31 Implementing inefficient allocation and population of a new array with a fourth value. 11:58:35 The function realloc simplifies the process of reallocating memory in C. 12:00:30 The use of realloc in C allows for dynamic memory allocation and copying without the need for explicit for loops. 12:04:32 Arrays and memory manipulation in computer science 12:06:20 Struct in C allows us to create our own structure in memory. 12:09:50 Creating a linked list with random memory positions 12:11:47 Use a sentinel value as a special signal for an invalid address 12:15:35 To enable backward traversal in a linked list, we can use a doubly linked list or make the list circular. 12:17:25 Using pointers in C to create self-referential structures 12:21:11 Using linked lists in place of arrays increases memory usage and eliminates the ability to index elements. 12:22:54 Binary search algorithm cannot be used when the data is not sequentially stored in memory. 12:26:10 Executing the provided code assigns a valid pointer to variable n. 12:27:53 Syntax for dereferencing a pointer and accessing a structure using arrow notation 12:31:22 Memory leak due to orphaned node 12:33:17 Implementing a stack using a linked list 12:36:52 Implementing a linked list of size zero and taking command line arguments 12:38:51 Converting command line arguments to integers using atoi. 12:42:28 Printing each number in a linked list 12:44:14 Iterating over a linked list using pointers and the null value 12:48:06 To avoid segmentation faults, use a temporary pointer for swapping and freeing memory. 12:49:54 Understanding the usage of while loops and for loops in iterating over nodes in a linked list. 12:53:23 Appending values at the end of a linked list increases the running time to O(n). 12:55:02 Maintaining a sorted list in a linked list 12:58:31 Binary search trees are structured like family trees and have special properties for binary search. 13:00:24 Using a two-dimensional approach for array layout and introducing nodes and pointers to connect them 13:03:56 Implementing binary search using a two-dimensional structure 13:05:45 Recursion is a beautiful technique for dealing with two-dimensional structures. 13:09:21 Not necessary to have pointers in both directions, but it can improve efficiency. 13:11:10 Implementing a binary search tree without balancing can result in an unbalanced tree with a height of N instead of log base 2 of N 13:14:39 Hashing is a final building block to achieve constant time lookup. 13:16:26 Sorting a deck of cards using bucketization and hashing. 13:20:16 Using linked lists improves the efficiency of contact lookup in a contact card representation 13:22:07 Hash tables offer efficient search time in constant time 13:25:49 Representation of nodes in the tree 13:27:35 Hash tables allow for constant time indexing and searching. 13:31:32 Tries are a data structure that combines aspects of arrays and hash tables. 13:33:21 Finding someone in a trie data structure takes a constant number of steps, regardless of the number of names in the data structure. 13:36:58 The try data structure is used to efficiently store and retrieve data. 13:39:00 Data structures are everywhere in the real world 13:44:03 Transition from Scratch to Python 13:45:46 Python eliminates the need for compiling code and allows program to be interpreted directly 13:49:05 Running python hello.py will print 'hello world' on the terminal. 13:50:50 In Python, the syntax for declaring variables and printing has changed compared to C. 13:54:22 Python supports format strings or F strings for automatic value substitution. 13:56:16 Python printing with curly braces 13:59:52 Implementing a spell checker in Python instead of C 14:01:38 Using a set in Python can be used as a dictionary for spellchecking words. 14:05:15 The C version of spell checker compiled faster than the Python version. 14:07:10 Using a more modern and user-friendly language like Python comes with a trade-off of potential performance loss. 14:10:46 Face recognition software can analyze and detect multiple faces, but can be trained to recognize specific faces. 14:12:44 Software can identify a human face by analyzing patterns of pixels. 14:16:21 Python has simplified the syntax for conditionals and introduced the 'elif' keyword 14:18:07 In Python, you can create a variable and set its initial value without specifying the type or using a semicolon. 14:21:33 Using the range function in Python is more efficient than hardcoding a list of numbers. 14:23:16 Infinite loops can be implemented using a 'while true' statement in C and a 'while True' statement in Python. 14:26:49 The default indentation in a Python file is left indented, and code is executed top to bottom, left to right 14:28:44 Python has a built-in function called 'int' to convert a string to an integer. 14:32:35 Python has solutions for floating point precision issues and integer overflow 14:34:31 Comparing values in C and Python 14:38:26 Explaining the usage of single quotes and double quotes in Python 14:40:17 In Python, you can use the 'in' keyword to search a list and it will return True if the value is found and False if not. 14:44:12 Python strings have built-in methods that can modify their values. 14:46:16 Strings in Python are immutable and cannot be changed directly 14:49:51 Implementing functions in Python using the 'def' keyword 14:51:34 Troubleshooting Python name errors 14:55:15 Code execution order in Python 14:57:04 Introducing Python's functionality to print a vertical column of bricks in the Mario game

[@divyanshm.2276]

This large comment and only 29 likes? leme' fix that...

[@titilolaajayi6072]

Appreciate your effort.

[@titilolaajayi6072]

Appreciate your effort.

[@doomed5206]

can I just say that he is probably the first professor/teacher that has my interest in learning throughout this lecture. loved it

[@inocybe6340]

(Copying progress over from old video to new) Day one: 2:18:00 Day two: 3:42:44 Day three (part 1): 3:58:00 Day three (part 2): 4:13:23 Day four: completed the challenging Mario problem! Day five: 4:41:00 Day six: 5:53:00 Day seven to twelve: sleep away summer camp, no progress made Day thirteen: 6:20:43 Day fourteen to eighteen: campingggg trip! Day nineteen: completed scrabble :D Day twenty: made wordle :) Day twenty-one: 6:41:52 Day twenty-two: 7:09:42 idk even know: 7:35:39 nice: 8:24:57 in english: 8:37:55 10000 years later: Finished Tideman >:) now: 9:23:17 in english again: 9:53:37 more progress: 10:39:28 on the way to state: 10:59:33 what a lovely fall: 11:26:33 I dunno: 11:56:22 asdas: 12:13:19 I’m bed: 12:53:30 zoopy: 13:19:12 finished data structure lecture: 13:42:44 finished speller! more progress: 13:55:26 cs50 in class: 15:30:28 my gf broke up with me :( man its cold outside: 16:54:18 cold couple of days: 17:33:38 haven't had school in a week, crazy storm: 17:51:14 finished SQL lecture: 18:18:30 first cemester in school over: 19:07:18 new stuffs pretty cool: 20:23:33 ok: 20:58:14 (I haven't been spending as much time on coding as I have been in the past few weeks. Hard to find time with all the running/biking that I am doing for xc season. Will hopefully finish this before school starts though!)

[@vladonutueu]

Thank you for the timestamps. You deserve praise, sir.

[@pistonfury]

This comment should be pinned to the top.

[@Chris-qb8kg]

Did ya finish :)

[@inocybe6340]

@@Chris-qb8kg lol not yet, but i'm very close

[@bug8008]

you spiraled

[@Dragonsky88207]

Amazing - thank you so much for posting this!

[@user-hu7ln8xe3h]

This is such an amazing opportunity made available to so many! Thank you for making quality education free and easily accessible, like it's supposed to be.

[@jasonfoster4083]

This is by far one of the best educational sessions I've ever witnessed. this guy could literally teach any age to any level. Very well presented. A HUGE thankyou

[@sergipapinashvili4592]

Perfect refreshed version, indeed pure masterclass

[@Ghostrider-ul7xn]

What's the difference between this and previous versions though? Aren't they all covering the same stuff and of the same quality?

[@skaliev6032]

This course is sooo well made! Thank you David and team!

[@yusufum_]

This is what education is. I really loved the atmosphere, the class, the instructor, all awesome.

[@JesusIsLove2512]

What a course! Professor David Malan is a blessing for learning, he really knows the art of teaching complex conceptual ideas into easy to understand and grasp. Thank you freecodecamp team for making this course available on KZbin, really appreciate it! Thank you and God bless you!

[@tubbs5015]

this is just phenomenal I mean this is some crazy stuff for completely free holy crap, thank you so much!!

[@anthonywinchell56]

Thank you so much to everyone involved in making this resource free and easily accessible to everyone. What a talented teacher

[@Excelsiorm.N]

Just finished Week O: Scratch which lasted about 2 hours. My temporary plan is to do a lecture a day (10 lectures total), then review the notes for that lecture twice then do any of the examples given in the lecture, then the following day do the next lecture and repeat. I'm 43 now and going back to school in 2 months to finish the last 5 classes needed for my Computer Science Bachelor's degree (lol, better late than never) at UMGC and have Python as my first coding language, so I needed a refresher to CS and an introduction to Python. I then plan to go for a Master's in either Health Informatics or Cyber security. On to Lecture 1 and notes review tomorrow an so on... Thanks for the awesome video @David Milan

[@Luke-ft2vl]

Very impressive!! Hope it all works out for you! I’m a senior in HS just trying to grab some concepts of CS and all that. I plan to do a finance/accounting major and CS minor in college next year

[@jerbear7952]

​@@Luke-ft2vlI am in finance. There is very little that AI won't be replacing here in just a few years. Especially in accounting. Do what makes you happy but even the things I am able to do with AI make most of my coworkers obsolete. Once Microsoft co-pilot explodes...man. a sincere best of luck to you man. You seem cool

[@fagan1031]

Just started how is your progress going?

[@DominickinCharlotte]

😂anyway do really hope u make it

[@IanNubbit]

The first 40 minutes have answered so many random questions I’ve asked over the years but never truly answered. Ill probably watch this over and over again

[@creatorofimages7925]

The Flask App Programming was done so flawlessly well. Absolutely a fan of this series!!

[@BugMateo]

This class is illuminating... thank you guys! And thanks to David, incredible instructor

[@gabrielgomesmabiala6707]

I love this harvard course can't get over it

[@Nest_Zen]

I like how these guys casually upload 20+ hrs content for *FREE*

[@francisfrancis1153]

​@@initializedis it the same one on edx? I doubt if you can access edx full content for free.

[@-r0mus5]

its not even their courses. Tbh all guides on this channel are only for people who are zero at IT and making big ass long vid about nothing

[@NBT2469]

@@initialized As is the course on the EdX learning platform. Worth looking into.

[@NBT2469]

@@-r0mus5 Yes. It would be nice, if the lectures were broken up into individual videos. For me, I am learning the Python programming language, so my focus will be on that lecture, alone.

[@-r0mus5]

@@NBT2469I mean the whole cs50 lectures aren't only about Python itself, but also about other languages. Tbh as the beginner its actually way better to start from lower level language and move on Python much easier than from Python to any other language which requires all the stuff about self allocing/freeing memory or pointers and other this type of stuff

[@PaulaS26266]

Thank you for the course. It's amazingly useful for me. I hope I'll manage to finish it and work on all my assignments. 😊

[@Samtation]

Just going to save this video for later. Thank you for the lesson in advance!

[@Phill_F]

This is one of the best uses of Technology on the Internet. Thank you for making this possible 🙏🏻

[@jkscout]

Thank you for actually showing what you are doing. I hate my university so much because all my professors rely on powerpoint slides and it makes my head hurt. This is so easy and enjoyable to follow.

[@anastassiaedel3974]

Omg yes, they just read the slides or even skip it and say you can look at it at home. Well why do i even pay then if i can just find these slides on github and use my time efficiently. Like i waste my time at school getting headaches and then basically have to self teach. This video is like everything.

[@mintchevvv1834]

Grass is greener moment

[@potatoeslol1216]

My professor for python had us copy and paste code from his GitHub lol

[@user-hz3gy4lx5m]

Is this a full cse course? Or just introductions of some classes?

[@agnidas5816]

@@user-hz3gy4lx5m it's 50. all courses in uni start at 101, 102, etc. so this isn't a full real course. and frankly he leaves out so much that he misleads you without teaching you. better off looking for python videos on YT

[@calvinnguyen5605]

Thank you so much!👍 Huge Respect!🙏❤️🙌🤝

[@micro-helper]

I have no words to express my feeling. But this free course is awesome.❤❤❤

[@elias8294]

Ok but this is probably the best explanation of SQL I've seen on the internet. Other people try to make it more complicated than it is.

[@anastassiaedel3974]

So true why do people keep doing that?

[@SpiritofanEagle]

// copied this comment for it to appear on top. Thanks to @jaimediez Key Takeaways for quick navigation: 00:00 Introduction to the CS50 course and Dr. David Malan's background 07:12 Transition to the C programming language in Week One 18:09 Exploring Different Number Systems 24:29 Introducing Volunteers to Represent Bits 31:10 Bits and Bytes in Computer Memory 36:01 Decoding Text Messages Using ASCII 43:59 Representation of Emojis and Skin Tones in Unicode 46:04 Efficient Design in Unicode for Complex Emoji Representations 01:17:00 Scratch Interface and Basics 01:25:20 Exploring Scratch Features 01:39:04 Interactive Programming with Video Sensing Introduction to using Scratch for programming. Creating a program with synthesized speech. Explaining the concept of functions in programming. Implementing conditional behavior in Scratch. 01:53:18 Iterative Development in Scratch 01:57:46 Introduction to Programming Paradigm 02:03:54 More Complex Game Elements 02:08:11 Evaluating Code Quality 02:14:56 Structure of a Code Editor 02:25:12 Transition from Scratch to C 03:02:01 Simplifying Conditional Logic 03:07:08 Exploring the structure of C code.* 03:09:30 Handling multiple conditions using "else if."* 03:10:28 Handling a catch-all condition.* 03:11:36 Recap and review of C code.* 03:14:09 Code optimization by eliminating redundancy.* 03:14:25 Recap of coding concepts.* 03:14:34 Addressing questions and clarifications.* 03:50:56 Break and Introduction to Mario ASCII Art 03:53:54 Printing a Column of Bricks 03:55:18 Printing a 3x3 Grid of Bricks 03:56:01 Discussing the idea of printing rows of bricks in a grid format. 04:14:29 Creating Functions with Inputs 04:49:23 Troubleshooting an error with get_string function, 05:21:57 Debugging with Breakpoints 05:22:25 Debugging in CS50, 05:26:46 Rubber Duck Debugging, 05:55:23 Introduction to arrays and for loops 06:15:15 Manipulating Strings in C 06:30:50 Introduction to converting characters to uppercase in C 06:35:12 Leveraging the ctype.h library for character manipulation 06:42:34 Command-line arguments in C programs 06:48:22 More fun with command-line arguments: Changing the "cow" to a "duck" 06:49:21 Exit Status and Error Codes 06:50:29 The Role of "int" in "main" 07:24 Understanding Algorithm Efficiency 07:41:42 Introduction to creating a phone book in C 07:43:33 Introducing the concept of a custom data type 07:59:00 Sorting Algorithms Introduction 08:08:00 Bubble Sort 08:18:10 Bubble Sort Analysis 08:27:04 Recursion and Recursive Functions 08:57:04 Time Complexity of Merge Sort 09:07:51 Introduction to Hexadecimal and Base 16 09:10:19 Understanding Hexadecimal Representation 09:19:54 Getting the Address of a Variable 09:44:01 Introduction to Data Types and Strings in C 10:03:55 Harnessing Pointer Arithmetic with Strings 10:17:37 Exploring string manipulation 10:19:27 Copying strings and memory allocation 10:47:25 Handling Garbage Values 11:09:12 Swapping values using pointers in C, 11:13:00 Memory limitations and potential issues in C, 11:27:18 Importance of Data Structures 12:24:03 Adding Elements to Linked List 12:34:00 Explanation of implementing a stack using linked lists, 12:44:00 Iterating over the linked list, 12:51:00 In this section, the main focus is on understanding the running time of various operations in linked lists. 12:56:00 This section introduces the concept of binary search trees (BSTs) as a way to achieve both binary search and dynamism. 13:12:24 Balanced binary search trees and algorithm complexity 13:18:06 Hashing and hash functions 13:24:38 Understanding Hash Tables and Memory Usage 13:41:41 Introduction to Python 13:56:53 Data Types in Python 13:59:54 Implementing Spell Checker in Python 14:11:12 Face Recognition in Python 14:19:13 Variable manipulation and loops in Python 14:26:53 No need for a main function in Python 14:33:41 Integer overflow and big numbers in Python 15:11:18 Python Printing Techniques 15:26:12 Python: Accessing Command Line Arguments 15:41:10 Introduction to Python Dictionaries and Their Use Cases 15:43:28 Swapping Values in Python 15:47:12 Working with CSV Files in Python 15:54:27 Text-to-Speech Synthesis in Python 15:57:36 Conclusion and Introduction to SQL 16:19:33 Improved Language Counting 16:26:29 Sorting Data 16:30:13 Interactive User Input 16:34:40 Introduction to Relational Databases 16:36:06 Basic SQL Operations 16:51:30 Introduction to SQL in Python 17:08:10 Database Design Considerations 17:11:42 Primary Keys and Foreign Keys 17:26:27 Querying Relationships 17:32:59 Joining Multiple Tables 17:43:37 Fuzzy Matching in SQL 17:45:03 Creating a database index for faster searches 18:01:29 Introduction to the use of placeholders in SQL queries 18:05:13 Preventing SQL injection attacks 18:22:31 Understanding the Basics of TCP/IP 18:44:25 HTTP as an Application-Level Protocol 18:54:06 Viewing HTTP Request Headers 19:05:27 Prank at Harvard-Yale Football Game 19:10:45 Introduction to HTML and Web Technologies 19:14:39 Running a Web Server with http-server 19:15:36 Accessing the Hosted Website 19:16:46 Understanding URL Structure 19:17:39 HTML Tag Hierarchy 19:21:48 HTML Elements and Hierarchy 19:31:07 Introduction to HTML Tags 19:32:29 Creating Lists in HTML 19:47:43 HTML Meta Tags 20:22:12 Introduction to JavaScript 20:23:35 JavaScript Variables 20:25:14 JavaScript in Web Development 20:25:56 Client-Side JavaScript 20:27:07 HTML Form Creation 20:29:56 Optimizing JavaScript Code 20:45:47 Dynamic table sorting with JavaScript 20:49:10 Changing background color with JavaScript 21:02:19 Folder Structure for Web Applications 21:17:15 Handling user input via URL parameters: 21:35 Using Templates and Layouts 21:48 Flask Web Development Basics 22:03 Template Layouts in Flask 22:07:18 Storing user registration data in a dictionary 22:10:18 Displaying user registrations on a webpage 22:34:55 Displaying Registered Users 23:36:23 Overview of Computer Science Course 23:51:38 Preparing for Post-CS50 23:55:51 Introduction to Review Session 23:56:19 Python "Hello World" Question 23:57:05 DNS (Domain Name System) Question 23:58:00 Merge Sort Runtime Question 23:59:08 ARG C in C Programming Question 24:00:19 File Opening Function in C Question 24:08:45 Valid Way to Print Exclamation Point Question 24:10:23 Compiling Steps Question 24:11:02 Surprise at the Beginning of the Halloween Lecture Question 24:13:20 Unicode and Emoji Introduction 24:14:28 Representation of Japanese Foods in Emoji 24:16:06 Universal Appeal of Dumplings Discussion 24:17:00 Introduction to Jennifer 8 Lee's Talk 24:20:33 Evolution of Emoji Discussion 24:22:13 Unicode Consortium and Emoji 24:25:20 Representation of Food in Emoji 24:27:17 Importance of Inclusivity in Emoji 24:37:32 Introduction to the Next Section 24:39:20 Memory Hierarchy 24:40:25 Storage Devices 24:41:31 CPU Clock Speed 24:45:15 System Architecture Quiz 24:48:33 Algorithm Efficiency 24:56:00 Recommended Books 24:57:52 Farewell and Good Luck 23:58:00 Merge Sort Algorithm Analysis 24:00:19 The Duck Debugger 24:03:00 How Strings Length is Computed in C 24:10:09 Arrow Operator in C 24:12:54 Missing Dumpling Emoji 24:16:21 Involvement with Unicode Consortium 24:29:02 Encoding Characters and Code Points 24:33:07 Depiction of Race and Nationality in Emoji 24:33:35 Evolution of Emoji Design 24:36:30 Contributions to Emoji 24:53:46 Emoji Directionality 24:55:36 Future of Emojis 25:03:07 Course Conclusion 25:09:54 Password Choices 25:10:23 Password Security 25:12:26 Cracking a 4-Digit Passcode 25:28:22 Lockout Mechanism

[@thabisombatha7663]

Okay I knew it would be fun but not this awesome!! Good job, great content, I'm learning

[@doinitlive3015]

I remember enrolling in a free harvard course online a couple years ago. The way they think and teach made me speechless, truly amazing.

[@jnicolettebailey]

This lecturer is awesome Have watched many of his online lectures - brilliant teacher!

[@adarax1]

Wow okay this is going to be a fun week. Thank you!

[@chefernandez563]

im watching the sql lecture as a refresher man did i need a refresher since now im learning javascript while also building my portfolio site its so easy to forget about the language i previously used for data

[@nkusters]

5:34:00 For those that wonder why the jumping into the end of loop section, it's because the do..while loop just does a je/jne in assembly, which occurs before the end of the loop. Bit of a disconnect between visually debugging your code and the way it's expressed in assembly.

[@user-hz3gy4lx5m]

Is this a full cse course? Or just introductions of some classes?

[@p3k1n0]

I took this course 3 (2 and a half to be precise) times on Edx in the past 5 years and I loved it everytime. They keep changing, adding, adjusting. Every year you find something new, something different.

[@reinertgregal1130]

Why take it so many times though?

[@p3k1n0]

@@reinertgregal1130 The first time I didn't finish it. The second time, a couple of years later, I arrived very close to the end, I had one lesson left. The third time, last year, I arrived at the final exam. Apart from the will to finish it completely, every time the course was different in some way. For example, now it uses a lot less C (like the first one I took it) and a lot more Python. And a good refresher on the basic stuff, every tree years or so, is not a bad idea at my age.

[@iulianviorelmosteanu2800]

@@reinertgregal1130 fun?

[@agnidas5816]

@@reinertgregal1130 it's not even a full credit course .. lol. it's 50 not 101

[@jordanmowry9164]

Thank-you for putting this information out there. As someone that completed a coding BootCamp, I was missing some of these foundations. This helped to fill in those holes.

[@user-tq5gi4ce1v]

Thank you guys for making our learning journey easier

[@ashtag4043]

The man the myth the legend. Pure respect for you sir.

[@bonganijele9770]

This is absolutely beautiful for people who are interested in computer science this professor deserves a huge thank you for uploading this cause for free.

[@cd6693]

Right now I am on my way to start this course! Big thank you for uploading it here, for free! :-)

[@gabrielt4334]

Thanks and Respect for everyone who has contributed their efforts to create and publish this video. All level of computer scientist should watch it! Highly Recommended!

[@lorisslow5582]

This is probably the best explanation to date. If only he also explained for us local users how to use the cs50.h file locally.

[@notnicex6685]

Yes, I couldn't really execute the code but i did follow along

[@lorisslow5582]

I've been reading The C Programming Language 2nd edition. Highly recommend it. @@notnicex6685

[@notweewee]

Download the library in your device then do "clang -o [name] code.c -lcs50" . So u just have to add -lcs50

[@notweewee]

4:51:11 here he explains

[@Juice_grows]

David is an amazing teacher. I took computer science a few courses at Oklahoma State University in 2010-2011 before I dropped out, but this CS50 is really helping me to understand some things I didn’t when I gave up all those years ago. I was doing some basic html for my current job and it really sparked my interest in learning coding again. It was my favorite class when I was in college, but physics and chemistry were so hard for me I decided computer engineering wasn’t for me. I wish I would’ve continued to learn things on my own for the past decade but I’ve learned that this is something I’m passionate about and am motivated to learn on my own through free code camp and then start with personal projects. All of the self taught developers have given me so much hope and motivation that I can do this if I put my mind to it and give myself time to understand it. Thank you, free code camp!

[@LuckyCooico]

Thanks for posting this.

[@andresesquivel5460]

(00:00:00) Lecture 0 - Scratch ⌨ (02:05:47) Lecture 1 - C ⌨ (04:35:19) Lecture 2 - Arrays ⌨ (06:59:38) Lecture 3 - Algorithms ⌨ (09:01:13) Lecture 4 - Memory ⌨ (11:26:33) Lecture 5 - Data Structures ⌨ (13:42:44) Lecture 6 - Python ⌨ (15:58:02) Lecture 7 - SQL ⌨ (18:18:30) Lecture 8 - HTML, CSS, JavaScript ⌨ (20:58:14) Lecture 9 - Flask ⌨ (23:19:07) Lecture 10 - Emoji ⌨ (25:05:28) Cybersecurity

[@dreamop823]

Key Takeaways for quick navigation: 00:00 Introduction to the CS50 course and Dr. David Malan's background 07:12 Transition to the C programming language in Week One 18:09 Exploring Different Number Systems 24:29 Introducing Volunteers to Represent Bits 31:10 Bits and Bytes in Computer Memory 36:01 Decoding Text Messages Using ASCII 43:59 Representation of Emojis and Skin Tones in Unicode 46:04 Efficient Design in Unicode for Complex Emoji Representations 01:17:00 Scratch Interface and Basics 01:25:20 Exploring Scratch Features 01:39:04 Interactive Programming with Video Sensing Introduction to using Scratch for programming. Creating a program with synthesized speech. Explaining the concept of functions in programming. Implementing conditional behavior in Scratch. 01:53:18 Iterative Development in Scratch 01:57:46 Introduction to Programming Paradigm 02:03:54 More Complex Game Elements 02:08:11 Evaluating Code Quality 02:14:56 Structure of a Code Editor 02:25:12 Transition from Scratch to C 03:02:01 Simplifying Conditional Logic 03:07:08 Exploring the structure of C code.* 03:09:30 Handling multiple conditions using "else if."* 03:10:28 Handling a catch-all condition.* 03:11:36 Recap and review of C code.* 03:14:09 Code optimization by eliminating redundancy.* 03:14:25 Recap of coding concepts.* 03:14:34 Addressing questions and clarifications.* 03:50:56 Break and Introduction to Mario ASCII Art 03:53:54 Printing a Column of Bricks 03:55:18 Printing a 3x3 Grid of Bricks 03:56:01 Discussing the idea of printing rows of bricks in a grid format. 04:14:29 Creating Functions with Inputs 04:49:23 Troubleshooting an error with get_string function, 05:21:57 Debugging with Breakpoints 05:22:25 Debugging in CS50, 05:26:46 Rubber Duck Debugging, 05:55:23 Introduction to arrays and for loops 06:15:15 Manipulating Strings in C 06:30:50 Introduction to converting characters to uppercase in C 06:35:12 Leveraging the ctype.h library for character manipulation 06:42:34 Command-line arguments in C programs 06:48:22 More fun with command-line arguments: Changing the "cow" to a "duck" 06:49:21 Exit Status and Error Codes 06:50:29 The Role of "int" in "main" 07:24 Understanding Algorithm Efficiency 07:41:42 Introduction to creating a phone book in C 07:43:33 Introducing the concept of a custom data type 07:59:00 Sorting Algorithms Introduction 08:08:00 Bubble Sort 08:18:10 Bubble Sort Analysis 08:27:04 Recursion and Recursive Functions 08:57:04 Time Complexity of Merge Sort 09:07:51 Introduction to Hexadecimal and Base 16 09:10:19 Understanding Hexadecimal Representation 09:19:54 Getting the Address of a Variable 09:44:01 Introduction to Data Types and Strings in C 10:03:55 Harnessing Pointer Arithmetic with Strings 10:17:37 Exploring string manipulation 10:19:27 Copying strings and memory allocation 10:47:25 Handling Garbage Values 11:09:12 Swapping values using pointers in C, 11:13:00 Memory limitations and potential issues in C, 11:27:18 Importance of Data Structures 12:24:03 Adding Elements to Linked List 12:34:00 Explanation of implementing a stack using linked lists, 12:44:00 Iterating over the linked list, 12:51:00 In this section, the main focus is on understanding the running time of various operations in linked lists. 12:56:00 This section introduces the concept of binary search trees (BSTs) as a way to achieve both binary search and dynamism. 13:12:24 Balanced binary search trees and algorithm complexity 13:18:06 Hashing and hash functions 13:24:38 Understanding Hash Tables and Memory Usage 13:41:41 Introduction to Python 13:56:53 Data Types in Python 13:59:54 Implementing Spell Checker in Python 14:11:12 Face Recognition in Python 14:19:13 Variable manipulation and loops in Python 14:26:53 No need for a main function in Python 14:33:41 Integer overflow and big numbers in Python 15:11:18 Python Printing Techniques 15:26:12 Python: Accessing Command Line Arguments 15:41:10 Introduction to Python Dictionaries and Their Use Cases 15:43:28 Swapping Values in Python 15:47:12 Working with CSV Files in Python 15:54:27 Text-to-Speech Synthesis in Python 15:57:36 Conclusion and Introduction to SQL 16:19:33 Improved Language Counting 16:26:29 Sorting Data 16:30:13 Interactive User Input 16:34:40 Introduction to Relational Databases 16:36:06 Basic SQL Operations 16:51:30 Introduction to SQL in Python 17:08:10 Database Design Considerations 17:11:42 Primary Keys and Foreign Keys 17:26:27 Querying Relationships 17:32:59 Joining Multiple Tables 17:43:37 Fuzzy Matching in SQL 17:45:03 Creating a database index for faster searches 18:01:29 Introduction to the use of placeholders in SQL queries 18:05:13 Preventing SQL injection attacks 18:22:31 Understanding the Basics of TCP/IP 18:44:25 HTTP as an Application-Level Protocol 18:54:06 Viewing HTTP Request Headers 19:05:27 Prank at Harvard-Yale Football Game 19:10:45 Introduction to HTML and Web Technologies 19:14:39 Running a Web Server with http-server 19:15:36 Accessing the Hosted Website 19:16:46 Understanding URL Structure 19:17:39 HTML Tag Hierarchy 19:21:48 HTML Elements and Hierarchy 19:31:07 Introduction to HTML Tags 19:32:29 Creating Lists in HTML 19:47:43 HTML Meta Tags 20:22:12 Introduction to JavaScript 20:23:35 JavaScript Variables 20:25:14 JavaScript in Web Development 20:25:56 Client-Side JavaScript 20:27:07 HTML Form Creation 20:29:56 Optimizing JavaScript Code 20:45:47 Dynamic table sorting with JavaScript 20:49:10 Changing background color with JavaScript 21:02:19 Folder Structure for Web Applications 21:17:15 Handling user input via URL parameters: 21:35 Using Templates and Layouts 21:48 Flask Web Development Basics 22:03 Template Layouts in Flask 22:07:18 Storing user registration data in a dictionary 22:10:18 Displaying user registrations on a webpage 22:34:55 Displaying Registered Users 23:36:23 Overview of Computer Science Course 23:51:38 Preparing for Post-CS50 23:55:51 Introduction to Review Session 23:56:19 Python "Hello World" Question 23:57:05 DNS (Domain Name System) Question 23:58:00 Merge Sort Runtime Question 23:59:08 ARG C in C Programming Question 24:00:19 File Opening Function in C Question 24:08:45 Valid Way to Print Exclamation Point Question 24:10:23 Compiling Steps Question 24:11:02 Surprise at the Beginning of the Halloween Lecture Question 24:13:20 Unicode and Emoji Introduction 24:14:28 Representation of Japanese Foods in Emoji 24:16:06 Universal Appeal of Dumplings Discussion 24:17:00 Introduction to Jennifer 8 Lee's Talk 24:20:33 Evolution of Emoji Discussion 24:22:13 Unicode Consortium and Emoji 24:25:20 Representation of Food in Emoji 24:27:17 Importance of Inclusivity in Emoji 24:37:32 Introduction to the Next Section 24:39:20 Memory Hierarchy 24:40:25 Storage Devices 24:41:31 CPU Clock Speed 24:45:15 System Architecture Quiz 24:48:33 Algorithm Efficiency 24:56:00 Recommended Books 24:57:52 Farewell and Good Luck 23:58:00 Merge Sort Algorithm Analysis 24:00:19 The Duck Debugger 24:03:00 How Strings Length is Computed in C 24:10:09 Arrow Operator in C 24:12:54 Missing Dumpling Emoji 24:16:21 Involvement with Unicode Consortium 24:29:02 Encoding Characters and Code Points 24:33:07 Depiction of Race and Nationality in Emoji 24:33:35 Evolution of Emoji Design 24:36:30 Contributions to Emoji 24:53:46 Emoji Directionality 24:55:36 Future of Emojis 25:03:07 Course Conclusion 25:09:54 Password Choices 25:10:23 Password Security 25:12:26 Cracking a 4-Digit Passcode 25:28:22 Lockout Mechanism

[@tonioswald]

Appreciate your effort

[@apuravsehgal2679]

I have just completed, watching this. This is very useful and helpful for my Job as a Manager and Possibly for fun, start working on my own game. Thank you so much.

[@unhappygilmore7129]

Thank you for sharing this knowledge.

[@Tekno1796]

This course seems to be amazing to anyone who wants to start in computer science. Thank you so much for bring this to the channel.

[@user-hz3gy4lx5m]

Is this a full cse course? Or just introductions of some classes?

[@Tekno1796]

@@user-hz3gy4lx5m I am not sure, but apparently looks very interesting for those who want to learn the basics of many aspects and topics from computer science.

[@koushikvenkata9272]

Progress - Day 1 31:10 Day 2 - 1:10:20 Day 3 - 2:38:28 Day 4 - 2:58:48

[@ellietny3238]

you stopped?

[@chickenleg1460]

The best lessons I've seen so far are amazinggggggg

[@GameSysterm]

amazing skills !!!!! just loved it

[@enockaddey]

Amazing 🎉🎉🎉 New entrants are blessed to have all these.... for freee! You don't have a reason not to make it if you apply yourself.

[@sreyag4766]

I have completed the first 40 minutes of this lecture and I bet no other teacher explained about the concept of bits and bytes better than this !!!. Thank you for providing it for free!!

[@1flybyguy]

Wow, a 25-hour video of the latest Harvard CS50?! Thanks! This must've taken a month to upload.

[@ToniTaku88]

What a teacher! Just imagine having this quality of teachers everywhere. Master class.

[@AJ-kg1hc]

On Coke?

[@4F6D]

Does it matter?@@AJ-kg1hc

[@xliquidflames]

This is so awesome. Im going through the entire couse using link in the description. I am doing the homework and practice problems and exams. I just wish I had someone to ask questions of and someone who could check my work. I just have to hope I'm doing it right. But I am not complaining. This is so awesome for being free. Thank you for posting this.

[@TVC-LOL]

Go to the description. I think there's a link to join their community.

[@stuartpatterson1617]

Use an ai. Paste in the code your stuck on and prompt Heeeeelp 🤩🤗

[@blankblank103]

You can ask away on places like stack overflow and there'll be plenty of people who'll help you (or make fun of you) lol

[@samaielechevalier4710]

i use chatgpt to check my work

[@freerights6695]

There's a cs50 discord with channels to discuss each problem set

[@morpheus_circuit]

excellent... inspirational... heartwarming... amazing... intelligent... best CS lecture in history

[@cxvxcbcxn]

This has reignited my desire to learn how to code! This professor is amazing! Everything he explains is so understandable, logical, love it!!!

[@toke7342]

Mom said 1 more video before bed. 😊

[@KopaFiuk]

What an excellent teacher

[@bengarner2659]

Massive respect to this yt. Video being released.

[@Music-sd1yz]

This is awesome!

[@nerdsong]

This is gold, please never delete it. It's a piece of art!

[@zafar2962]

Huge respect for Dr malan,I learnt fundamental programing concepts from his Worthy lecture

[@ethio-tech7028]

This kids are very lucky. I wish I had this kind of teacher for my CS class decades ago.

[@carolineseffen7458]

Thank you ❤ for your effort

[@mytube7473]

Brilliant !! This is how education should be. Free and Open.

[@koshobai]

I love the heck out of this. Fairly sure that the 4K HDR version is available on the @cs50 channel, but having it all here in a full 25-hour video is also A-okay to me. I learned a ton going through this and prefer it over the previous ones in which our beloved David Malan donned a mask. This one is much more sane to watch and truly makes CS approachable for the masses. Thank you to freeCodeCamp!

[@hersheynaik3029]

Yeah.. That Mask annoyed me as hell though.

[@mehranshah4856]

The amount of passion demonstrated by this teacher is something special. I also once possessed such a passion for my field wherein I just spent day and night thinking about and pondering over my area of study. Life wasn't just fair to me. Now, I am learning something that I don't enjoy the same way but have to make my ends meet.

[@seeriously001]

over 25 hours is crazy, especially when its a computer science course AND free

[@michaelpease2103]

I recently decided to start my journey in game development with unreal engine 5.3. I've always been afraid of learning to program. It seemed like this giant mountain of knowledge that I couldn't scale. I'm 32 now. If I don't start now, it'll keep getting more difficult to learn. I'm watching through the entirety of this course to gain a fundamental understanding of computer science. It isn't strictly necessary to learn this material, especially with unreal's blueprint system (visual scripting), to develop video games. That said, I am already gaining a better understanding of how to break down problems in a way that makes sense to the computer. Programming is so much like learning a second language. It teaches you to think in different ways: structure, syntax, etc. I am beyond grateful that this course is available for free on KZbin. Thank you!!

[@DailyShit.]

It will be a huge help to you because not everything is perfectly solvable with blueprint and it helps to understand the basic workings of languages and how the computer handles input and data. Also regarding optimization it is helpful to know if you go through unnecessary steps and bloat. Learning different paradigms can make you think of a smarter faster solution instead of a slow and easy one.

[@AnshParmar1]

for me 5:00:11 Compiling converts C code into assembly code. 5:01:53 AMD CPUs understand Assembly Language for efficient code execution 5:05:45 The code is stored on a virtual hard drive in the cloud. 5:07:54 The purpose of a library is to make it easier to use and reuse code that's already been written. 5:11:53 Code compiled into zeros and ones is not necessarily predictable, making decompiling challenging. 5:13:34 Debugging code is a lifelong skill and there are tools and techniques available to make it easier. 5:16:57 Debugging using printf statements 5:18:42 Using printf as a diagnostic tool in programming 5:22:09 Using breakpoints in debug mode to step through code 5:23:56 The debugger in CS50 shows variables and allows stepping through code 5:27:18 Using a panel to display changing values instead of print statement 5:29:07 The cs50 library prompts the user for a negative integer and stores the value in n. 5:32:52 Exploring the behavior of a 'do-while' loop in the program. 5:34:38 Using a debugger can help in finding bugs in code 5:38:11 Data types represent different types of data with a specific number of bits allocated to them. 5:39:58 Data in computers is represented using bits and bytes. 5:43:27 Memory in a computer is like a canvas for storing information in units of bytes or 8 bits. 5:45:11 Computing the average of three values using C 5:48:42 The video discusses the concept of memory and storing data. 5:50:33 Declare an array in C to store three integer values 5:54:26 Using loops to avoid repetitive code and improve code design. 5:56:21 Memory in computers is contiguous, and arrays can be passed as arguments in code. 5:59:58 Declare a constant variable to avoid hardcoding and easily reuse values. 6:02:01 Taking the average of a variable number of scores using a loop. 6:06:01 In C, you must remember the length of an array yourself. 6:07:58 In C, you cannot determine the size of an array when it is passed into a function. 6:11:31 A string is just an array of characters in memory. 6:13:24 Strings in memory take up one more byte than the characters typed by the programmer 6:17:12 Understanding operations on strings in computer science. 6:19:12 Strings in C are treated differently and have special implementations 6:22:59 Manipulating strings in arrays using new syntax 6:25:11 Calculate the length of a string in C 6:28:54 Introduce string manipulation and library functions in C 6:30:56 Iterate through each character in a given string, check if it is lowercase, and convert it to uppercase. 6:34:53 Using libraries in programming to solve common problems efficiently 6:36:42 Implement a program that's correct but better designed with fewer lines of code and lower probability of mistakes. 6:40:40 Introducing command-line arguments in the program 6:42:40 argc stands for argument count and is used to determine the length of the array of words typed at the prompt. 6:46:44 Command line arguments are used to modify the behavior of a program. 6:48:34 Command line arguments and exit status in coding 6:52:22 You can use the command 'Echo $?' to see the exit status of your program. 6:54:17 Cryptography is the art and science of encrypting information. 6:57:50 Encryption and decryption process explained 7:01:19 Efficiency of algorithms and its impact on solving problems 7:04:40 Searching algorithms and memory storage in computers 7:06:20 Executing the linear search algorithm to find the hidden 50 in the lockers 7:10:26 Using bracket notation, Jackson can treat the set of lockers as an array 7:12:06 Using binary search algorithm to find a number in an array 7:15:44 Divide and conquer approach for searching in an array 7:17:30 Binary search is more efficient than linear search 7:20:54 Algorithms perform similarly for large input sizes 7:22:39 Linear search has a time complexity of O(n) and binary search has a time complexity of O(log n). 7:26:21 Big O, Omega, and Theta allow computer scientists to analyze algorithm efficiency. 7:28:04 Translate the discussed ideas to actual code using arrays 7:31:50 Implementation of linear search in C using an array of numbers. 7:33:44 String comparison in C requires using a function called strcmp instead of == operator. 7:37:50 Avoid touching memory that shouldn't be accessed 7:39:40 Returning zero in main signifies code execution is successful 7:43:25 Using a 2D array to store names and numbers is a cleaner approach than combining them into the same array. 7:45:20 Code successfully searches for phone numbers in a phone book. 7:49:16 Defining a new data type called person using struct keyword 7:51:08 Creating a structure to store person's information 7:54:51 Read and update information dynamically from a file 7:56:50 C cannot set default values in struct, unlike more modern languages like Python and Java. 8:00:49 Sorting volunteers using selection sort algorithm 8:02:34 Using selection sort to sort a list of numbers 8:05:56 Bubble sort is a different approach to sorting that focuses on smaller problems. 8:07:34 Bubble sort algorithm to solve sorting problems 8:11:25 Counting the number of comparisons is a global unit of measure to analyze algorithms. 8:13:14 Number of comparisons to find the smallest element decreases by 1 for each iteration. 8:16:57 Selection sort takes N^2 steps in worst case and N^2 steps in best case 8:18:52 Iterate through the array from 0 to n minus 2 to avoid going beyond array boundaries. 8:22:30 Bubble sort has a short-circuit detail helpful for already sorted data 8:24:27 Sorting algorithms like selection sort and bubble sort have a redundant comparison process that results in slow performance for large numbers 8:28:14 Recursion allows calling a function on a smaller version of the problem until no more problems to solve. 8:30:05 Recursive search algorithm for a phone book 8:33:52 Implementing a pyramid drawing function using recursion. 8:35:49 Creating a pyramid recursively 8:39:33 The base case is important to prevent the code from running forever. 8:41:20 Recursion can be used with return values. 8:45:07 Merging two sorted halves 8:46:51 Merge sort requires additional memory for implementation 8:50:24 Sorting the left half and right half of the original input separately 8:52:19 Merging and sorting the left and right halves of the given list 8:56:09 The running time of merge sort is O(n log n) and it is better than bubble sort and selection sort. 8:57:56 Merge sort is generally preferred for sorting as it is faster. 9:03:45 Understanding computer memory helps in representing and creating interesting things 9:05:26 RGB color system: Red, Green, Blue 9:08:59 Hexadecimal is a base-16 system used to represent numbers beyond 0-9. 9:10:53 Heximal (hexadecimal) is a number system that uses 16 symbols to count. It is useful for various applications. 9:14:48 Hexadecimal is a base system used in computers to represent information. 9:16:35 Hexadecimal is commonly used to describe memory locations in computer systems and software. 9:20:11 Conceptually, the programmer knows that the number 50 is assigned to the symbol n in the computer's memory. 9:21:51 C language has operators to get the address of a variable and go to a specific address in memory. 9:25:30 A pointer is a variable that contains the address of a value. 9:27:23 The video explains the concept of pointers in C programming. 9:30:59 The code assigns the value of 'n' to variable 'p' using the address of 'n'. 9:32:42 Pointers are variables that point to something else 9:36:19 Arrays and pointers have a relationship, but are technically different. 9:38:07 Strings in programming are special as they store multiple characters and have a null character at the end. 9:41:42 String in C is actually a Char star 9:43:30 Defining data types in C using type def 9:47:13 Pointers in C are declared using the star symbol and can be dereferenced using the star symbol. 9:49:00 Printing the address of a string using the %p format specifier 9:52:40 The 'percent s' is used in printf to print the characters in a string. 9:54:39 The video discusses the concept of addresses in C programming. 9:58:19 Printing characters from a string using pointers

[@NickRayC]

It feels like I can absorb more information in this video, than I could from my full CS degree I did with honours about 7 years ago. Coming from a respectable university, the lecturers are completely mediocre compared to this guy, and his ability to relay information. There are actual props he uses to explain things rather a bored, burnt out sounding professor sitting behind a desk, reading through a re-hashed slide deck, wishing he was researching rather than teaching. And the biggest difference is that this guy actually sounds like he CARES about what he's presenting, and it's kind of sad how unique this is, considering the amount we pay to sit in lecture theatres around the world. This video is a game changer, I wish it was around when I went to school

[@4F6D]

I'm currently studying CS (struggling hard thats why I'm here) and I think its his attitude what makes it so easy to learn when he teaches. It's easier to stay focused when someone is that motivated.

[@elvessilva9805]

Professor like him deserves to earn millions. No discuss.

[@user-vi2fp6dl7b]

Thank you very much!