03 - Elementary Problem (Dynamic Programming for Beginners)

[@andreygrehov]

Next video: kzbin.info/www/bejne/h523ZXt9bph6l9k Previous video: kzbin.info/www/bejne/ZoXYXnqIgsSfe5I

[@sairamankilambi5007]

I've been searching for dp tutorials and I have to say this is the best dp tutorial ever... Really appreciate it👍

[@andreygrehov]

Thank you so much, Sai

[@pythonxz]

What a beautiful way to break down how to define the kinds of problems dynamic programming helps with.

[@darshantawte7435]

Best DP course I have stumbled upon.Keep up the good work Mr Andrey!!

[@starbloods0013]

I'm so happy I found this course. I love my school but sometimes my professors can't really explain concepts that well. You explain things so well! Thank you!

[@mrrobotnik_]

Thanks for the tutorial, i'll be waiting for more videos, keep doing them. Much appreciation from Brazil. Bom Trabalho.

[@andysong8085]

func nSumRecursion(n int) int { if n == 0 { return 0 } if n == 1 { return 1 } return n + nSumRecursion(n-1) } Hi Andrey, I will contribute one Recursion version of nSum. I think pretty much someone is looking for recursion version as DP always be couple with recursion at the same time. Hope my contribution makes sense to you.

[@shritishaw7510]

please let me know whether I am right or not combinatorics problem means "HOW MANY WAYS ARE THERE TO DO A JOB" and optimization problem means "WHAT IS THE BEST POSSIBLE WAY TO DO A JOB"

[@damaroro]

sweet jesus , I've been looking for very beginner DP programming course for a weeks, since I'm not from CS background, I found many DP course in youtube is really HARD, but this is an exception, I would love to see more Data structure and Algorithm course from your channel, you're such a good teacher

[@yexijiang]

Curious how do you stay focus while the kids are around. That's also an important skill to work from home during this time period.

[@andreygrehov]

Oh man, that's a good question. It's tough, but luckily, I have my own "office" - a small room where I both record these videos and do all the work.

[@yaxlu]

Watching these videos in loop - very well done. Glad I stumbled upon them. Thank you ( a ton of times) for making these videos. Please keep doing it (more).

[@pedrocolangelo5844]

I found out your dynamic programming lectures playlist today and I am so excited about finishing it! Going to the 4th lecture right now. Thank you for posting these!

[@TheAmron90]

Wow I have never understood the fundamentals this well. Knowing the problem statement well, it was easier to understand the solution. Usually videos are describing a complicated problem at the start, which makes it difficult to understand. Thanks :)

[@saraahmed408]

Thank you so much, DP was giving me such hard times! I watched a lot of videos, but yours are the ones that made me understand! Thank you

[@theremin1441]

linear runtime: def sum(n): return (n+1)*(n/2)

[@cutiex7357]

WHY is this so therapeutic 🙈 Love it!

[@andreygrehov]

Haha, thank you, @Cutie :)

[@ichekaozuru1979]

Thank you, Mr Grehov. I love your channel. Thank you for this awesome series.

[@Mridul2k24]

Thanks for this great video lecture series ,these lectures are really helpful . Lots of love and appreciation from India.

[@AkkumBakkum-m5h]

i m in love with dp after watching your videos thank you so much

[@acidroot7126]

Free great tutorial, thank you! It’s really cool explanation !

[@mohammedalhaj1516]

this course is very beneficial, great work thank you for your time.

[@Benjamin-Chavez]

Thanks again. This course is exactly what I needed.

[@mfandrade]

Awesome lecture! Thank you so much, Andrey!

[@Enzoerb]

What an amazing course!!

[@rahulyadav8159]

Loved your explanation.. Waiting for next cool video.

[@shashankdhanai7608]

first time using dp this videos are really helpfull...

[@amrilsan9299]

Sir, your tutorial is very easy to understand, Big Thanks

[@subid.majumdar]

Best lectures available on internet, please sir make more videos on different topics

[@yeffdev]

Hi Andrey, any books with exercises and examples you recommend? Many thanks for your content!

[@raghavddps2]

Awesome video Andrey! Thank you so much for this course. On a side note, can you please suggest some good resources to learning GoLang ?. Thank you again for the Awesome content.

[@andreygrehov]

Thank you, Raghav. As for Golang, here is a super quick intro to the language: tour.golang.org/welcome/1 The next step would be to go through a course or read a book. Here is a small book that is available for free: www.golang-book.com/books/intro It's slightly outdated, but a lot of stuff still holds. Also, check this link out: golang.org/doc/ It has a ton of useful up-to-date information. Go is a small, but very powerful language. One can learn it within a day or two.

[@raghavddps2]

@@andreygrehov Wow, thank you for these resources too. You are just awesome! Thank you so so much.

[@mariestolk3794]

Your videos are amazing! Thank you so much for making these :)

[@sandippaul100]

Great video... So the concept is we are storing previous results for future use. In some sense can I say that we are reducing time requirements by using extra space?

[@virtyaluk]

Excellent work. Thank you.

[@604motorsports]

Thanks for the video. But, in this case, there is no benefit as you have to sum from 1 to n anyways, so what is the benefit of dp in this case or other cases?

[@mihirsidhdhapurasensei]

Amazing. my fundamental now super solid. thanks to u sir;)

[@ladydimitrescu1155]

Awesome course!

[@StackJobs]

明白了。动态规划核心思想就是拿到一个大问题，先从这个大问题的一个小问题开始，小步迭代，推导出后面的问题和当前的问题的函数关系，最终把整个大问题都解决掉。

[@StackJobs]

Thank you, nice explanation. I got it.

[@jerrycheung8158]

great lecture, thanks Andrey. For the example you gave, is it also a recurrsion problem? How do I differentiate these 2 types of problem?

[@Alexey1st]

Why did you create array with size n+1? The loop works while i

[@andreygrehov]

The n+1 is needed because of the base case, we store it at index 0. If I were to find the sum of only 1 element, the subproblems array would contain [0, 1], hence two elements (n=1 but the array size is n+1). Here, check it out: play.golang.org/p/z3RZyk8BS3v Does it make sense?

[@Alexey1st]

​@@andreygrehov Yeah, make sense. Thanks a lot for your efforts! Very appreciated.

[@goshapoopkin]

thank you for doing this, it is really appreciated. can i just ask what language did you use to write the code?

[@andreygrehov]

Thank you. The code is in Go Programming Language.

[@bouzekriredouane485]

why not using a simple loop like that : int sums(int n){ int result = 0; for(int i = 0; i < n+1; i++) result += i; return result; }

[@andreygrehov]

As I said, the problem in the video is just for demonstration purposes only. We obviously do not need DP here, it's just to let you feel what DP is.

[@JustVideoClub]

Hii bro i am learning dp in python and now where can i get that code

[@monishnjs]

How many ways and find maximum are same right?

[@recce-tp9zj]

Great Videos.

[@anubhavsethi3416]

Looking forward for more videos

[@andreygrehov]

Working on it

[@nyashachiroro2531]

4:51 That was a perfect definition Jesus 😂

[@32ask92]

thank you for your help really appreciate it :)

[@glensee7506]

I love it, thanks!

[@sap1363]

great video. Which keyboard do you use ?

[@andreygrehov]

I use Macbook Pro.

[@natnav3436]

Hi, this is a great course. I tried to do the example in java using your technique and I was able to solve it public int addFirst(int n){ int[] h = new int[n + 1]; h[0] = 0; for (int i = 1; i

[@andreygrehov]

Good job! Yes, that is still considered DP. In fact, you optimized space complexity from O(N) to O(1).

[@natnav3436]

@@andreygrehov Thank you

[@ConernicusRex]

In Swift: func nSum(_ n: Int) -> Int { guard n != 0 else { return 0 } var dp: [Int] = [0] for i in 1...n { dp.append(dp[i - 1] + i) } return dp[n] }

[@josueteodoromoreira8921]

Thank you so much!!!

[@ethernet764]

Code in C if anyone wants: int nSum(int n) { int *dp= alloca(1 + (n * sizeof(nSum(n)))); dp[0] = 0; for (int i = 1; i

[@salmaelziady4386]

what kind of programming language is this? what ide is this?

[@andreygrehov]

Programming Language: Go (go.dev/) IDE: Intellij (www.jetbrains.com/idea/)

[@glennpavel4800]

good job

[@MukilShelby]

so underrated channel....

[@hocineabderrahmane3027]

int sum(int *numbers, int n){ if(numbers[n] != 0) return numbers[n]; if(numbers[n-1] == 0) numbers[n-1] = sum(numbers, n-1); return numbers[n-1] + n; }

[@erikdali983]

I wish the code was in Python or C++.

[@VishalJangid1]

"What is the maximum profit gained by buying and selling a stock?" this can be solved by divide and conquer

[@II_xD_II]

pref sum

[@edwardduong6914]

Somehow you look like Victor Perkins to me.

[@andreygrehov]

lol

[@RedOxBangla]

C language code #include int sumf(int n){ int dp[n+1]; dp[0]=0; for(int i=1;i