Recursion in Programming - Full Course

[@michaelcamp2870]

Around 13:20 is exactly the kind of explanation that I was looking for. I understood how recursion works when a human does it, but not how the computer would handle it. The call stack stuff cleared this up for me. Thank you!

[@best1000]

I have watched many videos on Recursion and i can assure you this is the best way that has been explained Recursion so far. Thank you all provided and posted this video here so that million of people can universally learn this.🙏🙏🙏

[@reapermerc8337]

0:00 "When learning about recursion, it can seem like you are going back to the beginning" XDXDXD Why is no one talking about this neat pun

[@vivekpuurkayastha1580]

Same thought here ... :smile:

[@laurinneff4304]

They should've also made the clip play a second time

[@jamalarshad147]

I just watched for 23mins and it's explained so clearly that I feel it's the best video on recursion that anyone can watch on YT.

[@snehashishghosh7258]

The way in which the lecture has been made is awesome... From the smallest of concepts to advanced concepts. I enjoyed learning.

[@marklord7614]

This is what the education system needs. Well-put-together courses that are accessible to anyone with a computer. I'm sure you'll continue to get likes and subscriptions well into the future because of this gem. Well done.

[@raghavsharma2762]

THERE CANNOT BE A BETTER VIDEO A RECURSION. YOU EXPLAINED ALL THE CONCEPTS AND PROBLEMS SO WELL.

[@advaithsahasranamam6170]

This. is.... BEAUTIFUL. ABSOLUTELY BEAUTIFUL LIKE DAMN. Why isn't anyone teaching like this guy? Hats off to you!

[@pravatyadav3623]

Google algo needs to put this video on top when searching for recursion

[@aditya_asundi]

Yeah

[@double_courage57]

Change your region to USA in youtube settings :D

[@polimorphic13]

The analogies and snippets of code are truly amazing. Thank you for this course!

[@jasonistheking]

I feel like the first 5 minutes of this video helped me understand recursion better than my CS classes in college. I ended up switching tracks away from CS because I couldn't wrap my head around recursion and trees...

[@looming_]

You cannot understand trees or graphs without recursion. It takes some practice, but becomes quite intuitive once you wrap your head around it.

[@GrantH2606]

@@looming_ Some of us never wrap our heads around it

[@looming_]

@@GrantH2606 me from 2 years later… it’s a doozy haha

[@animemotivationx]

In the beginning when I started learning programming I didn't think recursion is that much important but when I started to learn DSA. I figured it out recursion is the soul of DSA and now I am learning, I have crossed 1:30 hr video and it has been so much fun and easy to grab. The tutor is really good ...

[@Codenames560]

Agreed man, the worst thing I've done was trying to attempt tree, graph and linkedlist problems without a complete understanding of recursion.

[@ru2979]

1:30:00

[@billiamreynolds]

Man thank you so much for your explanations of how recursive calls work on the call stack, and then also how to interpret the call stack through debugging. This cleared up so much confusion for me!

[@chhavimanichoubey9437]

yes this fucking video was needed by many people like me who still doesn't understand recursion and have no idea how to contemplate this.

[@dimam.4960]

okay, you all telling that you understood recursion and all of this. but let's appreceate the man for finally explain us why Stack Overflow is Stack Overflow :D

[@xzoldik]

This the best tutorial of recursion I have ever seen on youtube such a great simple explanation really from zero to hero

[@shukrulloabduqodirov4353]

Aynan Uzbda yetishmayotgan proekt bolibdi. Omadilarni bersin! Alloh adashtirmasin. Ohirigacha hayrli haloli bo'lsin!!!

[@chewbacca9783]

The best Recursion Video available on internet. Thanks for making the video.

[@haruka3203]

I am mind blown. I almost never use recursion because it felt so alien to me, I've done everything in for loops, while loops, etc, but mostly for loops. I've never seen so little lines of code typed for something very very complex! This makes me rethink how I program. Rather than seeing what's in front of me, but taking a step back, identifying a pattern, using that pattern flow to your advantage, adjust the course of the river and viola you've done it.

[@sret919]

I guess functional programming works like that. Bartozs Milewski was talking about what you are describing here, it reminded me that.

[@mylaramvenkatesh9796]

There are no words to praise you about your explanation and content, Really Mind blowing for me, Super content thank you man

[@informativecontent4778]

26:00 Equivalent Python code to check palindrome, this is just a simple approach but we can translate it into recursive approach: name = "racecar" check = False for i in range(1, len(name) + 1): if name[-i] == name[i - 1]: check = True else: check = False print(check)

[@jmbrjmbr2397]

I have already commented but I want to comment again.. How good is this lecture? It's unbelievable. Thank you so much great people, I love you so much

[@vnaveenkumar982]

the first statement itself changed my entire perception, towards recursion.

[@ricric4722]

Right 😂😂 It was a nice pun

[@servantofthelord8147]

This video explained the call stack excellently! Recursion is one of those things I just assumed "oh, it's difficult so nobody really get's it other than theoretical researchers, so I don't need to really close that knowledge gap, but in fact this video showed me it didn't need to be so difficult. Great job!

[@akmzahidulislam2764]

Just wonderful! A brilliant teacher who is wholeheartedly passionate and industrious about teaching. Result? You watch this.

[@ahmedbello6298]

Thank you so much for the video. This is the best explanation I've got on recursion after several books and KZbin videos. The analogy where people were waiting in a queue (for ATM) is in my view what set my mind free on how to go about recursion. Now I know how and why a problem is attacked recursively. Cheers from me!

[@nidhalmejai346]

the examples with which you explain and visualize the call stack was the most important part in this tutorial i think the call stack was the part we all missed when learning about recursion and you just explained it carefully and clearly thank you for the efforts you have put in this video.

[@TheSimpleEngineer]

Glad you enjoyed!

[@synapse9869]

​@@TheSimpleEngineerhey man great video can you tell me which debugger plugin you used to display breakpoints ?

[@musicmelody1085]

0:39:27 if(left>right-1) is the correct answer because if we write code(left>right) and give input 20 is not in array the loop can run again and again show the Error!!👌

[@jmbrjmbr2397]

This is an extremely high quality, precious video. I haven't studied cs in uni, but I highly doubt the education is this high quality there.

[@raunakmitra7868]

The ATM analogy was very elegant.❤️

[@Archius_09]

I sometimes feel guilty as i dont pay any fees to them and yet dont have time to study all this things :(

[@girlgotTECH]

You are the voice of my soul

[@utkarshkukreti239]

You have to study in order to get the skill and then earn from your skill then you can pay and don't feel guilty.

[@Archius_09]

@@utkarshkukreti239 i am a student and my education comes first of all

[@djay00009]

Don't lie. I know newton's a genius

[@ferhatbeztout1447]

Isaac Newton what're you doing in the 21th century ?

[@ethiopiangirl447]

def binary(n): a=[] a.append(n%2) if n

[@ethiopiangirl447]

this code interestingly only returns 0, for all the times its supposed to append n%2 to a, it does it but eventually it returns zero. I have the working code but I dont know why this is peace of code is behaving like this... It's python, Decimal to binary question.

[@MrVernuk]

Awesome course with explanation about how actually works well known data structures using recursion! Hats off, man :)

[@sojanmathew5875]

Decimal To Binary Code (at 30:00 ) can be simplified (without passing result parameter) String findBinary(int decimal) { if (decimal == 0 ) return ""; return findBinary(decimal /2 )+ (decimal % 2); }

[@idc20627]

Im surprised factorial wasn't amongst one of the examples. This resource plus the MIT lecture on youtube regarding recursion has cemented this tool for. On to the next tool!

[@Shil131]

will you be able to share the mit lecture video link?

[@tirupatirao7521]

This is simple and crystal clear to start with. Dn,t underestimate as it is long video.it’s 200% wort

[@prasunkumar1434]

Every time I am in search for a topic, FCC comes with a video. Thank You FCC for your efforts.

[@mrbadmanzaman]

Great video, helps explain recursion clearly using good examples and diagrams. I use it to help teach recursion in my A level CS classes. I recommend trying to implement the examples in code (I used Python) to help better understand the examples. The instructor also uses a good clear tone of voice with the right amount of pace so it is easy to follow the explanations.

[@TheSimpleEngineer]

Thanks!

[@Abhi-qi6wm]

def print_tree(self): if self.root: self._print_tree(self.root) else: return 'Empty Tree' def _print_tree(self, curr_node): if curr_node: self._print_tree(curr_node.left) print (str(curr_node.data)) self._print_tree(curr_node.right) My implementation of the print function for a binary tree

[@ankitshrivastava3672]

what a timing, I am just finishing the last section of freecodecamp js DSand Algo certification and I feel like there should be a separate section on recursion, here it is...thanks a lot

[@avijeetkumar1585]

yeah same here

[@JeanFrancoisDesrosiers]

Been coding since 1997: recursion is good for academic purposes but almost everytime I saw it in a product, it was a source of bugs due to usage of stack above limits, which limits are very difficult to guess. Each f call is on stack.

[@TheSimpleEngineer]

There are definitely trade-offs. In some of my professional work, we've dealt with data structures that are tree and graph-based (ie. graph databases and the algorithms that need to be built around the data) where traversals are inherently more elegant and easily understood via recursion, whereas the iterative counterpart is a mess and often impossible to conceptualize with loops. The risk is memory, but when the bounds are understood, you can make an informed decision more appropriately. This is also true with a lot of taxonomy work when you're dealing with schemas, for example (trees).

[@samCoder]

I would suggest not to simply nullify the topic. Yes, you won't use it much but it's great for concept building. FYI, I recently used Recursion in my project. I was bulding a component to show hierarchy using Tree-grid.

[@juliolopes2062]

I tried using the decimal to Binary example at 31:14 in a for loop and in the recursion way he showed, and tried to use the function for big numbers like pow (99, 99), it worked but recursion executed 3 times slower than the for loop, and increasing the number, to pow(99,150) I get a stack error. So, I won't use this at my work at all. Only in case I might need to use with something related to graph.

[@TheSimpleEngineer]

@@juliolopes2062 Definitely good to evaluate why and when it's a good choice to use it. 3x slower on modern day systems for small amounts of data is negligible. Think 5 nanoseconds vs 15 nanoseconds. However, on large datasets, recursion will of course be slower. Cheers! Nice work on investigating the performance.

[@ADITYA-fk1zy]

using relative analogies and debugger to explain call stuck made it easy for me understand,Thanks simple Engineer

[@firdousaslam2173]

this chanel is responsible for soo many people's career OMG

[@pew4410]

16:58 start

[@bac9982]

Like many other comments, the simplistic breakdowns of recursion in this video help make sense of this topic for even the most confused. I thoroughly enjoyed this video and wish this could get bumped up for more of the world to see!

[@mouaz_ahmed_siam]

really this is the best video i watch it until now about RECURSION Thank you for these explains

[@shankarghimire4492]

Thank you so much Ryan for sharing your knowledge with the world! Very amazing content and explanation! :)

[@RahulSharma-lw2ss]

Best ever video for entire recursion concept

[@Ferndalien]

Recursive: re-kers-ive prefix re - repeated, suffix - ive having the nature of curse - to invoke the wrath of a deity or to express feelings with an expletive example: "all my code is recursive when I'm debugging it."

[@Ericsicons]

Thanks for the great content! It covers so many different areas of software development.

[@uniqueanshu4268]

Nice man

[@atharvpal7038]

One of the best lectures I have ever seen. Thank you very much!

[@edwinroman30]

I'll put a comment to remember through out your likes, that I watched this incredible master piece about recursion 🎉. Great job, thanks for this amazing lecture!

[@F.R.A.N.K.I.E]

This is such a comprehensive course. I understood recursion better than i ever thought I would. THANK YOU!

[@indraxios]

I got the feel of recursion in first 3 minutes

[@jasmine9538]

It took me about 5 replays to for the linked list reversal to click. But when I had my "ah ha" moment... chef's kiss! 😚Amazing!

[@servantofthelord8147]

WOAH! The ATM ANALOGY WAS EVERYTHING FOR ME! I wish I saw this when I first started learning about recursion, hahaha, thank you very much!

[@davidwalker6960]

Excellent. Recursion has always been a mental twister for me. Trying to master it now, to make it a normal part of my thought processes when developing. Very informative, easy to follow. Thanks!

[@slurpeesauce1750]

Makes programming way more fun thank you

[@galibmahim9544]

Very nicely explained. Well for me The ATM example quite describes in on itself what recursion is then the stack memory that computer has explains why it works like last task to the first. Again very good. Appreciate❤

[@sret919]

This is an icredibly high quality and valuable, precious video. I love internet, I love youtube, I love these nice people teaching with this much quality

[@mamdouhaiesh4584]

in order to be important in this world you have to understand the most difficult concepts not the easiest ones and you think you are awesome at this point

[@abdourahman87]

Thanks to the simple engineer now that I really understand what recursion is all about. You really made my day today :)

[@gregorywilson2124]

Marty Stepp used the same counting analogy to teach recursion: great approach

[@aarondiaz2506]

No words, thank you, can't ask for a better teacher🙌

[@caiocutrim3596]

what's up guys? This content is amazing, I'm really impressed with the simplified approach. I'm learning a lot.

[@saikumarrr5]

Thank you for the content. It's really helpful to change the perspective while trying to solve a problem.

[@satestactmathtutor6570]

i enjoyed how you show the stacks and did alot of examples.. big big thanks from Egypt

[@mrboyban]

Well done mate! Better than a so called "UK Top University"

[@7Saints78]

A very well-thought-out video. The animations are really helpful. However, one major flaw for me was that the instructor does not show you how to create the code. He takes the pre-defined code snippets and explains them through animations. This explanation is genuinely helpful, but while actually implementing the code by ourselves we need to understand the correct way to approach the problem. The theory in the beginning can only do so much. All pre-defined coding sections impose the idea of the solution without inducing the challenge of coding from scratch. This in a way forces an indirect rote learning principle. Pupils will always try to recreate the code snippet they understood, but will not try to create a solution by themselves.

[@Spaaace]

You know, when I first started out with the self-taught path, I was told "GO TO FREE CODE CAMP, they are GREAT". And I didn't listen. I've seen many many MANY tutorials after 2.5 years of this (awesome) journey, and I gotta say.... reeaalllllllyy wish I had listened. You guys ROCK! It is incredibly rare to find a tutorial that can even try to keep up with the quality of learning your channel/org offers. It is smooth and concise and most importantly, accurate. Thanks for the content, and I will always lead those who are curious to your doorstep first.

[@user-zr6jm4ld9l]

In a paid bootcamp right now and I completely agree.

[@miresoman1769]

@@user-zr6jm4ld9l What does it mean to be incompletely agree?

[@user-zr6jm4ld9l]

@@miresoman1769 thanks. It was an autocorrect I didn't catch. I fixed it.

[@millsdickson8498]

Wow, recursion...done! Thank you so much for this very excellent presentation! I now have a solid foundation on this matter.

[@SaschaRobitzki]

Great course! Following along in C++ and it works very well.

[@alkhiljohn7640]

These guys deserve an award :)

[@switch3]

Type annotations are invaluable but I just can't help to admire the simplicity of Python. def binary(num): if num

[@djay00009]

A whole course of recursion. Awesome

[@RatioBozo69]

Progress: --> 34:32 --> 1:29:10

[@muntasirmahmudsaif6239]

on 26:48 pseudocode for other language function isPalindrome(str) { if (str.length < 2) { return true; } if (firstCharacter(str) === lastCharacter(str)) { return isPalindrome(middleCharacters(str)); } return false; }

[@optomal7]

Every time I take this course it feels like I've taken it before.

[@sherazdotnet]

Great great beginning of video. Very nice explanation of what recursion is and how to think in recursion. Liked how the code is explained using graphics which helps understand what the code is doing. But, it'd have been great if no code was displayed for any given problem first and discuss what can we do to solve the problem. That's what's the most challenging part. Take Merging Sorted Link List example. The code was shows right away and we are walked through what the code is doing. I think more interesting part would have been to discuss the approach and then come up with a solution. But I must say that this video so far is the best in explaining Recursion.

[@me-lx8ei]

Leyton

[@KirubelTamene]

⭐ Course Contents ⭐ ⌨ (0:00:00) Introduction ⌨ (0:00:42) What Is Recursion? ⌨ (0:00:50) Explaining Recursion via ATM Analogy ⌨ (0:04:56) Explaining Recursion via Essay Revision Analogy ⌨ (0:06:22) Summarizing What Recursion Is ⌨ (0:07:15) Why & Why Not Recursion ⌨ (0:10:57) Understanding The Call Stack ⌨ (0:11:32) Call Stack Analogy ⌨ (0:16:35) Recursion With Strings Introduction ⌨ (0:16:50) String Reversal Explanation ⌨ (0:20:47) String Reversal Call Stack Animation ⌨ (0:22:59) Palindrome Explanation ⌨ (0:25:46) Palindrome Call Stack Animation ⌨ (0:27:46) Recursion With Numbers ⌨ (0:28:02) Decimal To Binary Explanation ⌨ (0:31:12) Decimal To Binary Code & Debug ⌨ (0:34:33) Sum of Natural Numbers Explanation ⌨ (0:36:17) Sum of Natural Numbers Code & Debug ⌨ (0:38:51) Divide & Conquer Algorithms ⌨ (0:39:27) Binary Search Animation & Explanation ⌨ (0:43:50) Fibonacci Explanation ⌨ (0:45:54) Fibonacci Animation ⌨ (0:49:07) Merge Sort Explanation & Animation ⌨ (0:53:21) Merge Sort Code & Debug ⌨ (1:09:36) Linked Lists ⌨ (1:09:49) Linked List Reversal Animation ⌨ (1:14:48) Linked List Code & Debug ⌨ (1:19:52) Merge Two Sorted Linked Lists Animation ⌨ (1:25:53) Merge Two Sorted Linked Lists Code & Debug ⌨ (1:29:02) Trees ⌨ (1:29:14) Insert Value Into Binary Search Tree Animation ⌨ (1:31:32) Insert Value Into Binary Search Tree Code Walkthrough ⌨ (1:33:43) Insert Value Into Binary Search Tree Call Stack Animation ⌨ (1:35:11) Print All Leaf Nodes Explanation ⌨ (1:37:02) Print All Leaf Nodes Code & Debug ⌨ (1:41:09) Graphs ⌨ (1:41:21) Depth-First Search Animation ⌨ (1:42:58) Depth-First Search Code Walkthrough ⌨ (1:45:38) Recursion Optimizations ⌨ (1:45:44) Memoization & Caching ⌨ (1:47:59) Tail-Call Recursion ⌨ (1:50:48) Conclusion

[@ArunKumar-ds6di]

I just realised that I do recursion when learning only to end up with a stackoverflow of browser tabs ;)

[@SumanPokhrel0]

I am just starting DSA , and u just dropped a gem , thank you so much 🤟🤟

[@hiranyam]

Sir, You killed me @4:12 , I cannot forgive you for that, I’ll just love you.

[@drewperotti]

Thanks for the vid, I've had a hard time with recursion and this is really helping.

[@inspirationalquotes5840]

there is a mistake in Palindrome the method should be return isPalindrome(input.Substring(1, input.Length -2));

[@brianpwnsjustin]

It's not wrong. subString in javascript doesn't include the actual index for the second parameter.

[@nonconsensualopinion]

@@brianpwnsjustin He's using Java. Your observation still holds.

[@rachadelmoutaouaffiq8752]

its shameful that people are actually disliking such videos ...

[@RaheelJunaid]

It's a good thing KZbin counts dislikes as user engagement; recommending the video to more people :)

[@insist1754]

may be CEOs of paid courses

[@sestremADB]

It must be people with mouse's problems.

[@jasonking1284]

Recursion is a bullshit technique....

[@insist1754]

@@jasonking1284 what is better than it?

[@iiimiiim]

I love the ATM example. Thanks!

[@pygeekrfoo820]

the Fibonacci explanation was masterful

[@christopherchu2516]

wow 3 minutes in and i absolutely love the analogy you used. it explains recursion so well and so easily

[@NotesNNotes]

This was great - even in 2023, it helped me work through the nitty gritty :) Much appreciation freeCodeCamp and the Simple Engineer :)

[@ithinkthereforeitalk935]

You really think that fundementals can change in a few years? Bro, it's not fashion trends, the programming concepts are literally the same as the were 50 years ago.

[@williammcenaney1331]

The ATM example is excellent. But I think a recursive function calls a copy of itself. If it does that, its recursive definition is circular.

[@evachild]

Great refresher for interview practice!

[@Moses_coder]

Good work, simplifies what seems to be complex stuff

[@mohamedgad4291]

on *39:39* , when you calculate the mid you should add the ( left ) value to the calculations

[@besherkhayat2190]

This is what amazing content is...but I think there is a mistake in the palindrome code...in the recursive call I think we should use str. length()-2 instead of str. length()-1

[@tamirb7020]

Possibly it’s because the substring goes from 1 to str.length -1 where str.length-1 is not included

[@carefree_ladka]

substring () doesn't include the last index

[@besherkhayat2190]

@@carefree_ladka no it does..at least in c++

[@SauravTiru]

@@besherkhayat2190 in JS it excludes the last index

[@besherkhayat2190]

@@SauravTiru ok thank you bro

[@vikramc08]

Thanks a lot for your effort! It is really helpful video. And I can see how with great patience, you explain recursion on different topics. Thanks again!!

[@SylvainBrunerie]

All these examples look super interesting, but I just want to point out that tail-call recursion optimization is super important to know, even though it’s kinda briefly mentioned here. Really sad that’s it’s mostly not supported in JS yet. Have a look at Elm if you want to safely use recursion in the browser :)

[@eclecticspirit4803]

best video to understand recursion

[@noelhdez3640]

Broooooo. Literally you read my mind!!

[@gigachad400]

Best video on recursion!!