4.9 Longest Common Subsequence (LCS) - Recursion and Dynamic Programming

[@LetsBeHuman]

Give this man a medal. In 23 minutes, he covered all 3 ways and DP with 2 examples. Just couple of suggestions to win much more subscribers 1) For your videos at least allow auto-translate 2) Instead of directly pasting the code, you can do think-out loud and tell us how you arrived at that code. Man, you deserve a round of applause.

[@trango1658]

many thanks from MONTREAL xxx

[@bipinbhandari8781]

True!

[@soumilyade1057]

and also, how to code for memorization. One such example would clarify the concept even better.

[@narharimotivaras79]

true bro! Hatsoff to this Man!

[@azadalishah2966]

Soumilya De Memoization ( not memorisation). It means store the result in data structure of ur choice and read from it in next call instead of recalculating again & again. Thus it become faster. If u r not clear let me know.

[@prachid3990]

This is the 60th video I am watching from this playlist, and literally have not come across a single negative/criticising/jealous comment!! Such is the aura of an amazing professor!! Thank you Sir!

[@dhruvpatel9957]

Attended zero lectures but understood everything from you. I'm a fifth sem student and.....god bless you sir 🤟🤟🤟🤟.

[@harshjoshi6257]

bhai lecture bhi par lena

[@dhruvpatel9957]

@@harshjoshi6257 8th sem mai aa gaya bro clg khatam hone ko aayi hai.

[@harshjoshi6257]

😂

[@sarthakgaba1583]

😂

[@karanbhatia6712]

@@harshjoshi6257 Aye tu jaa re! Yaha bhi aa gaya

[@mateussoares7421]

Hello Abdul, how are you? I'm writing this comment just to say that I loved you video and I'm very grateful that there're people like you ready to share knowledge for free that's gold!!!! Thank you very much!

[@charlesrodriguez6276]

I'm not afraid to say that this man single-handedly got me through algorithms. Thanks for being my and the world's algorithm teacher. You are certainly up to the task!

[@brooks201]

😂the the

[@pionerogroup9081]

I didn't understand anything in my class when my teacher was teaching this topic and I did not even try to understand because I knew that It will be clear only by Abdul sir's videos. You are Great man

[@techinframes]

so now tell me what didi you understand

[@anon00089]

@@techinframes longest common subsequence, duh

[@scholli99]

this guy really understands what he is talking about, unlike the others! Thumbs UP!

[@TheAndreve]

From México, I agree with all the previous comments. Your explanation is clearer than my algorithms course. Great job sir!

[@vigneshp9994]

So Mr. Abdul Bari has decided to single-handedly save me from all those unhelpful college lectures. Good, Very good. Thank you :)

[@praneetsingh9695]

you are one of the best teacherr ..happy teacher's day sir

[@DivyanshuShekhar]

I develop, design and lead efforts for various initiatives at Oracle. Even with 13+ years of experience I come back to this amazing man to appreciate his simplicity. Dear Sir, Your simplicity in explanation is infectious. It motivates me to go back to college one more time and appreciate how amazing it is to learn from a teacher like you. God bless you. :) :)

[@digvijayrajput7970]

Hey man , you work at Oracle ? 🤩

[@shanthansai6377]

The dislikes are from the lecturers/professors who can't teach as good as him.

[@ManishKumar-rz9ub]

🤣🤣🤣

[@kapilgupta8543]

No, few dislikes are because he just shows how algorithm works. Instead of showing how one can approach the solution without knowing solution already. Because approaching the solution is more important than mugging up solution. For example, he just showed the code for recursion without explaining one can think of writing that code without knowing the solution already.

[@FranVarVar]

​@@kapilgupta8543 I think that cannot be taught. You just make tables with examples, fill them manually and try to see a pattern. That is my guess but I am not an expert!

[@rahmasamy7463]

@@kapilgupta8543 exactly

[@foodiebala1434]

My madam explained it in more detail like him as well but I am going to these for revision. So, not every teacher is like u all thought if u listen to them carefully they will also cover all these topics

[@saunakroy2587]

Watched all your KZbin videos from scratch. Teaching in that way, which is simple to understand and will also be quickly absorbed by the students is an ART. You have got this brilliant ART sir. I have grasped all these concepts before college via your videos. Thanks a lot for providing knowledge for free. You are a real teacher and i hope that you will continue teaching us more through your videos.

[@coopjmz9627]

Best algorithm teacher ever! Gotta love the dramatic way you turn to the camera at the end of your videos, when you know everything is explained and all the viewers understood!

[@onkartiwari5742]

I did not no about this gem earlier. how easily he explain the things. thank you so much sir. May god give you all the happiness.

[@archardor3392]

Amazing! How come I have never thought of this solution! So trivial it seems but only when presented to you by such a master! Days, no Weeks of confusing and trying it on my own and now I see clarity! Amazing presentation!

[@eccheong]

You are my role model in explaining concepts Teacher Abdul. Interesting, clear, and well-paced. I can't thank you enough for sharing this for free. I appreciate you and hope one day I can contribute to maintaining your courses.

[@singhvivek5098]

If a beginner in Dynamic programming want to learn the logic behind this problem i think this is the best video to clear your logic dont waste your time on other videos and watch this entire video your doubts will be cleared .....All the best to you ...

[@demiguo6752]

Hi Professor Bari--THANK YOU SO MUCH for the videos!!! I'm currently a cs undergrad student taking basic algorithm, and I'm very confused by what I'm learning from school. But I'm so glad I found your videos because you made every algorithm SO CLEAR to me!!! I'm cramping for my midterm this coming Tuesday and having a meltdown because I'm so confused about the algos and your videos saved me. THANK YOU for all your great work!!!

[@SouhardyaSutradhar]

Can relate. I have my midterms tomorrow. Where are you from btw?

[@sarthakmahale1802]

​@@SouhardyaSutradhar 🫤

[@mayurbajaj5517]

Great to see you here Sir, I have attended your classes in ACE for DBMS and CN in 2011 and let me tell you I still hold the notes from your classes and are very very helpful for any interview prep. Thanks a ton (bow)..!!! One suggestion I would like to give for this video is in case of DP solution if you could have explained how the code is derived that would have been more understandable.

[@krishnendudutta1465]

Which college?

[@140_kenguvabhavesh]

brother,if possible can you share the notes?if yes,do reply i'll send my mail id

[@hoddybhaba6704]

I have been struggling with LCS understanding and this person has made it look like a cake walk. This is the best explanation.

[@emwhite_devil2289]

Bro can you explain to me why sir taken lcs as "ONE" and not a S in the Sequence Is there a reason in second question

[@b088mohdzaid5]

I watched MIT lecture on dynamic programming multiple times but this 23 min video cleared all the doubts I have.

[@小郭子游戏-v4r]

too good. I wish all the professor can do and explain like you, so I can understand LCS long time ago. Thank you so much

[@bizzey2714]

I’m doing my master's in CompSci and these videos help me in undersyanding the working of the problems so well -- my prof is so so bad omg

[@madinab3610]

OMGSH, YOU MAKE IT SO CLEAR. Thank you so much for all your hard work with finding the correct examples and making this video so neat and short, but complete. Thank you soo much!

[@chinmaydas4053]

You are the best sir...one problem with ways solution..just great. Lots of respect..

[@nitishroy6538]

Arey ye itna aasaan hai :) sir, huge respect... guru purnima pe apko naman hai

[@aashishdagar3307]

I have tried multiple resources,but you are best sir. Time investing here on this channel is worth. Thanks you sir.

[@vikasjha8975]

this man is doing great job by helping students with his videos may god fill his all dreams. best wishes )-

[@sarksou]

Sir, I saw this video after watching multiple dp youtube video but somewhere there was gap. But you're amazing, from today any topic first I will search in your channel.. You're too good if there is a match add 1 taking value from previous diagonal else max of previous row/colum.. Superb too good.. Bottom up, top down too good. I wish I watch this video before my amazon interview

[@philipanderegg5973]

This guy is single-handedly giving us all our CS degrees despite the terrible profs some of us have in our algo uni courses! Props to this guy, liked and subbed 👌

[@himanshuharinandanshukla5543]

our college needs a professor like You Sir ji. Please Complete a series of PYQ of GATE C & DSA. ap hamesha happy and healthy rhe sir ji

[@pastafarian8410]

Thank you mr.Bari. Last time I had watched your video , I picked up a very little. Now I could understand thoroughly because I had worked out this problem and it cleared my all doubts and I can apply it some other problems . Moral of the story is work out more problems and come to a such an intelligent teacher .

[@muzammilmueen3487]

Awesome .. The best part is that he spent good amount of time to clarify what is the 'actual problem' he will solve ... 10 / 10.

[@GauravMahajanAvaron]

FINALLY! A video that doesn't have super-technical language and the entire method is so easy to understand.

[@chiragsingh9166]

The way he teaches is amazing. I failed to understand this topic in my college but you are the man who helped me understanding this topic I m first semester student of BVoc(software development and E governance) Thanks sir 🙏🏻❤️

[@ShortsAddict382]

i saw many videos to solve lcs problem but did not understand, this is the only video that i understand, aap bahut accha padhate hai sir

[@Sol3Z]

I love you😂 I got this video in my recommendation 1 hour before my exam and this problem was the "hard" task of my exam :)

[@RaymandShojaie]

This man is a legend, cant say anything more!

[@ethanhyde3872]

I thought I'd never understand this buy Abdul is an absolute lifesaver. Round of applause

[@MustafaKHAN-sw1xb]

This tutorial is better than others

[@sameersondur9030]

I really appreciate your way of teaching. Not even for a moment, you made me feel like this is a very complex topic. I have seen very few teachers teach this way. This makes me think how to communicate better with my colleagues. I think the opposite person should not feel like it is a complex issue.

[@andreysaenko9057]

just want to say - WOW. Very clear description of LCS problem.

[@jimmyp4584]

We can’t thank you enough sir. Simply can’t. Such simple and beautiful way of explanation of complex topics.

[@crazyprofz]

Thanks sir, your explanation is awesome. I love how you explain every single step using hand writing. Clear concept, this is all I need, the rest is just need to convert it to any programming language. I hope you are always healthy there

[@venkateshnagubandi754]

One of the best Teachers for programming on KZbin

[@nraghu99]

You are the best sir, like someone said, congress has to give you a medal fpr spreading the light

[@utkarshpaliwal411]

Sir, you are God. The way you explained the problem moving from Recursion to DP, explaining at each step the ways in which we can better the current solution, helped me understand this question which used to give me nightmares. Thanks a lot !

[@mirrannas.6892]

After a horrible horrible lesson about this topic and leave with confusion, I am watching this video and finally understand the topic. Thank you so much ❤️

[@darshanyadav7727]

after struggling through lot of documents, this video gave me complete and satisfying answer.😊

[@minhazurrahman8592]

Never understood the diff between memoization and tabulation,thought they were both dp approach.I've just learnt it right now!Best explanation I've found on the internet till now!

[@shabashachi1238]

Sir, what are subjects , you are teaching? Your teaching method is best. If I listen your video, Then no class, no book is required.

[@Ayushsharma-qc7qx]

Just pure teaching best in the whole universe and also in multiverse 🛐

[@rishabhbandi3368]

Sir you are God Gifted. By only listening to your videos before exam brings back the confidence. Not everyone can teach as calmly and confidently like you! Thanks a ton for being saviour of so many students.

[@uditkumar7211]

Sir is legend what my teacher couldn't explain in 3 lectures Sir explained in 23 minutes Hats off

[@Jay-jf4ux]

This man teached us a 2hour lesson in just nearly 30 min. 💐💐💐💐 Bravoooo

[@prashanthikuchana4144]

There are lot of videos on LCS but this the best and clear explanation I've seen so far. Thank you and my respect to you sir.

[@allahakbar9580]

I am not even a computer programmer and I understand what he's saying! He's wonderful!

[@Mayank612722]

In my yesterday's exam, recursion and LCS weighed 24/80 marks. Your other videos really helped me. Thanks. Subbed.

[@Mayank612722]

Abdul Bari Sir I was revising using your videos all through 18th April night till early in the morning of 19th. Thanks for the work you do. Thank you.

[@ahmedalif9989]

Just awesome!!!! My university's lecturer was failed to explain it and made it hard for everyone. You make it so easy as possible. Hats off sir!

[@yuxinzhang5094]

Best algorithm tutorials I've seen. Lots of respect!

[@abhinavjha3828]

Sir You are the best Professor I have ever seen teaching in this simple and effective way

[@welcmasher2471]

Thanks!

[@PhuongNguyen-mg8ss]

Thank you so much, Sir. Your lectures helped me survive in my class during Covid-19:x

[@mansmor7211]

This gentleman is teaching better than my Uni lecturers. He deserves special thank you.🙏🙌🥇🥇🥇🥇

[@divyanshsharma8983]

Sir, you are the first person who made me think about dynamic programming so comfortably,....TONS OF RESPECT

[@AwesomShots]

Never got this much easy explanation of recursion. Thank you so much sir for the video

[@gringoire986]

Seriously the way this guy explains is the best.

[@chetanraikwar3546]

Best videos on programming I ever found on youtube. Thank you sir, your videos are very helpful in competitive programming. :) After seeing your explanations, I can write correct code on my own. . . . ^_^ Lot's of respect. Please make videos on :- 1. Longest Increasing Subsequence 2. Longest Palindromic Subsequence 3. Edit Distance

[@nickharalampopoulos]

Hello Bari, you are one of my favorite teacher, and one of the best on youtube. Thank you for all your efforts.

[@aminurrahmanashik2786]

This man deserves a medal.

[@ehsanhosseini5861]

This is the greatest video I have ever seen. Thank you Abdul, you are the best.

[@niteshyadav247]

Pay attention to how he uses plain recursion first, then memoization reduces number of calls(2^n --> m.n), and then he uses dynamic programming which is still O(m.n) but it outperforms recusrsions because recursive functions take a lot os space on the call stack and are generally slower tha for loops, every new way of solving the same problem adds to the performance, i used to jump directly to dynamic programming without understanding the problem it solves you can only truly understand(and appreciate) dynamic programming if you're coming from recursion

[@yessinekammoun1997]

Lovely explanation, you have just explained in 23minutes what my teacher didn't explain in 2 hours :D

[@poojaarora6912]

Sir, all your videos of ADA are really very well explained. I will pass in my exams only because of you.... Lots of respect and love to you!

[@Tuscani2005GT]

Thank you so much for this amazingly clear explanation. If I had to pay in order to subscribe to you I would do so happily!

[@md.fazlerabbi675]

sir you are best. this ALGO course cost me 24k. but my course faculty even don't know what he is teaching. thnx sir

[@finfan2101]

Honestly speaking, this is better than Tushar Roy's explanation.

[@DridhaNishchay]

You are great Sir. Saviour of all students. Hats off to you. Thank you.

[@ayushshukla3000]

went to 3 places and here I found the simplest of explanation Thank You Sir

[@bryanmax9]

Thank you so much! Your explanation is awesome and easy to understand. professors like you are the ones who create the best students!🙌

[@cpsarathe]

LC explanation is the best i saw here. god bless you brother .

[@rentedunicorn]

This is the best explanation I have seen for LCS.

[@atheist00123]

Was Trying to figure this algo out. I have never seen anyone teach better.

[@anirudhreddybasani3555]

Probably u are the only one who have made such a large number of videos on topics related to competitive programming...lots of respect🙌 sir

[@jasonghent98]

Abdul is brilliant. Wow. I wish dp was as intuitive for me as it is for him.

[@zeroone8137]

Simply superb. I felt like your lectures were similar to ravindra babu sir's lectures.Both of them lectures are very useful to understand the concepts very clearly. Hands off

[@khadijahalsmiere3718]

you saved my life Sir .. thank you very very very much .. //from KSA .

[@Jaxkr1]

Best algorithms channel on youtube.

[@koushiknallapuneni2564]

Dynamic programming 15:05

[@nikhilbalwani2285]

@@abdul_bari :)

[@umangverma3660]

😂😂😂😂

[@devangpatel8406]

@@abdul_bari are sir 😂😂😂

[@lavishgarg4274]

@@abdul_bari aap alag nhi mann rhe ho sir😂😂

[@nournote]

Thanks very much. That was crystal clear. I have a remark though : as far as I know, ameliorating recursion with memoization is still considered DP in the literature.

[@AfroMuggleKing]

exactly!! dp can be done using tabular method(bottom up) or recursion with memozation(top down). Got confused when he said now will do it using dp.

[@SoyJayP]

I understood it right away watching this video after spending a long time to understand it from other blogs.

[@coledrain2158]

My lecturer just explained it to us vaguely. But now I see why some things happen. Thank you Sir.

[@vatsraviya470]

Thank you sir you helped me in passing my exam

[@金不二]

OMG, this algorithm is so awesome. And the explaination is crystal clear. Much appreciated!

[@Anubis10110]

Thank you so much Sir, I really wish you all the best. Easy demonstration and great explanation .. Wish I can give you the Golden Medal in Teaching.

[@skubydubydu]

Please make more videos. Your explanation was the easiest to understand among all the videos I have seen for this algorithm.

[@sazzadhossain2257]

Thank you sir for your hard work .You are helping students like me all over the world . Great tutorial.

[@jimmymemon]

This man is an Angel. May Allah bless you!!

[@mini22q11]

Hats off sir :) I have done my btech in 2010 that time i afraid to read DP but wen i started to read with ur videos they r quick one :)