4.2 All Pairs Shortest Path (Floyd-Warshall) - Dynamic Programming 

you're a perfect example of how a CSE Teacher should be.

In less than 15 minutes you managed to clearly explain something my professor couldn't explain in an entire semester. Eventhough I'm late relative to when this video was uploaded, I still wanted to take this time to thank people like you, who provide an invaluable service to us all.

Sir At 6:39 I think for A^1[4,2] the value is 5 but not 8.

Dear sir, You have been an incredible help in my studies. I didn’t understand my courses very Well Because the teacher wasn’t the greatest, But Thanks to you i was able to pass all my finals! I am so grateful for these amazing video’s and i truly hope you Will continue to make such Good video’s! You are one of the best teachers when it comes to algorithms, bravo!

I am just passing my algo exams because of you sir. Thank you so much...

thanks, sir ! hats off to your efforts, you are providing quality lectures on algorithms.The best material available on youtube would say .

Greetings from southern California! You make learning algorithms so much easier and interesting! Thank you for your great work, Abdul!

I just started watching your tutorials and even though they are a lil longer compared to other tutorial channels, its soo worth it. You have such awesome insight on the concepts. Thank you very much. Keep up the awesom work

Thank you so much! the instances of matrices is a unique way of teaching this and made me understand instantly! Much better than starting with the algorithm and following from there. Bravo!

Your ability to clearly explain algorithms is very effective. One of the best teachers I've come across. I look forward to your other videos.

I have never been so jealous in my life How lucky they are whom have the opportunity to attend your classes . Truly, you are the best professor ever ! thank you so much

Your students are lucky to have a professor like you. I wish all my professors thought CS like you do!

You are so humble, explanations are simple. This shows the skill of an awesome teacher- explaining anything such that anyone can understand. 🙏

sir i think at 6:39 for A-1[4,2] there will be 5 not 8

Thank you so much! Your videos are well titled and by far the best explanations on RU-vid. PS: Love those long pauses where you look at the camera like a professor giving a student time to absorb it all.

Thank you so much for making these videos! It's crazy how much better I understand Floyd-Warshall now

Very good logic, very clear explanation, very nice example, makes me understand the idea immediately after watching the first half of the video without having to check other information. You're one of the best lecturers I've ever seen!

This could not have been a more concise and clear lesson. Thank you sir

Thank you professor for this wonderful explanation! Your videos mean so much to students all over the world. Greetings from Politehnica University of Bucharest ! (Romania)

Didn't understand anything in a 90 minutes lecture, immediately understood the algorithm after just 4 minutes of this video. You're legendary

Really appreciate your effort of such a patient explanation. This really helped me to understand the problem that I wouldn’t figured out maybe for hours merely by reading book.

When comparing the Floyd Warshall method with the Djiktra method , i think there are 3 important things you should have pointed out : 1) The Djiktra method can be achieved with less complexity , especially with sparse graphs . By using binary heap as a priority queue we achieve O(n*m*logn) and with a fibonacci heap we achieve O( (m+nlogn)*n). 2) The main advantage of this method compared to Djiktra is that it can be implemented in a graph even if we have edges of negative weights ( as long as there are no negatives circles ) . Djiktra is highly limited by that aspect . 3) The best algorithm for this method which benefits both from 1,2 is : Johnsons . It can be achieved in O( (m+nlogn)*n) even if we have negative weights ( no negative cycles )

I must have watched a dozen videos on Floyd Warshall and this is the only one I actually understand... THANK YOU SO MUCH!!!!!

Probably the best explanation of Floyd-Warshall algo, thank you!

I shared a link of this video to my professor........and next day he thanked me.

Thank you sir, I have final exam for my algorithms class next week. You're a great supplement for me when I try to understand the materials. Greetings from the U.S !

Respect, You made some of the concepts so easy to understand... That I should have known 20 years ago but skipped it in school because it was hard to grasp.. thank you very much for all the clarity... Amazing quality

The best thing happened to me today was stumbling upon this channel. I was just not getting the Floyd-Warshall explanation from wikipedia. The explanation here is crystal clear.

Wow! What a phenomenally straightforward explanation. Hats off to you, Abdul Bari sir!

Btech walon ke liye masiha ho aap.

his videos have been saving me so much time and effort. wish all professors could be as good as him!! many thanks

Soft and gentle tone with clear explanation

Correction A1 matrix (4,2) = 5

My Algorithms teacher was struggling big time with this one lol. And here, sir Abdul Bari explained it perfectly in 14 minutes. Great teacher!

In one word. Brilliant! I wish you were my algorithm professor. I have an Algorithm exam in 2 days and if I hadn't seen your videos I would probably fail. You made this course super easy. Thank you so much for everything sir.

That's by far the best explanation I've found. Thanks!

Well, ngl, it's kind of impressive finding people who can really explain things even better than our teachers! I can finally rest assured if I missed something in the college.

How come he makes every algorithm so simple to understand, much respect sir!

Thank you! This solved a problem I was working on, beautifully and quickly.

Whenever my exam comes I see your videos one day before. There are no words for complimenting you. Thank you so much sir for your hard work and dedication!!!!! All teachers should be like you......

Thank you very much sir for such a clear and efficient explaination.. I'm Truely benefiting from it!

this type of lectures in India for us this is really heaven sir

Abdul bari uplaods videos so long without applying any additional ads. Great Man!

Thank you so much. I understood more in the first 4-minutes of this video than in any of my network flow classes.

Thank you sir I liked ur videos bkz you aren't only trying to make money by these videos. You are putting lot more efforts to teach us in an easy manner.

Mr. Bari: Thanks so much for your videos. They are very clear and concise, and help me learn these concepts way faster than my expensive professors ever could. You are a god send! Thank you so much for what you do.

Your videos are really good. Both your language and content are really clear, and that is something i can appreciate.

This is a person who actually wants us to learn algorithms. Thank you very much.

Dude you rock! I was going to end my life but after watching your video you gave me hope.

i submit my all assigment after watching your algorithm videos,thats really helpful.👍

I literally spent 1 hour right before my exam looking at your videos and understood everything I needed to know highly recommend the dijkstra prim kruskal floyd lessons were amazing.

Sir, thanks to your amazing lectures, I was able to clear my algorithms subject! I don't know what I'd have done otherwise. Keep up the great work!

Sir your amazing.....wish we had teacher like you in our college!

finally i understand this algo...thank you so much

I wish i had someone like you in my college, all of us deserve a teacher like you, you're just phenomenal, thankyou sir for teaching us❤️✨

I gave up the lecture videos from my professors and watched yours. Super helpful.

I love you, you magnificent creature. You saved both my degree and love life.

in video - at 8:36 AND 8:38 they changed the value of A'[4][2]=5 , don't get confuse...

One of the best Teachers......cleared all my doubts..ws able to complete my syllabus 2days before exam..

excellent Explanation , In a single go i understood i didn't need to watch this video second time. Thanks Bari

It says something and I mean REALLY says something about exceptional teaching ability when you have a teacher whose accent is this thick but is vastly superior in facilitation of core concepts than the most elegant English speaker. Mr Bari. You sir are the best teacher of computer science on the web. Period. There are people who pay tens of thousands of dollars for years only to fall short in what you can manage help us achieve in mere hours.

I am at almost the end of this semester. Every time after our teacher's lecture, I come here to build the comprehensive concept :")

The way your teaching is super sir!!! Getting the points is very easy ,,,thank you.

Your videos help people all over the world! Thank you sir!

You are teaching better than our teacher respect ,🙇🏻‍♂️

I've exam in 2 hrs and now I understood why he's called the God of Algorithms

Apparently university is just an expensive subscription to youtube. Do unis find teachers who can't teach on purpose to get more money from people retaking the course? Sir, you've been saving my grades for 3 years now! I cannot thank you enough for making such great and easy to understand content. Thank you !

I watched a few videos, this is the first one that made any sense. Thank you 👏 Because of your breakdown, and well done explanation this got a like and a subscribe.

correction A^1[4,2]=5.

I am an undergrad student at IITD I was really having a tough time understanding this but this video made it so easy.....

thank you very much, this was much better explained than from my own professor. Greetings from Berlin, Germany

Searched all of available explanations on youtube and found this one which is perfect. Normally, I stay away from indian accent videos. Thank you sir for very detailed video

Great experience sir. Plz upload more videos

Thank you for the beautiful explanation. One observation: Isn't the time complexity of Dijkstra to find all pairs shortest path same as that of Floyd Warshall? I think the only advantage of FW is that it can also find it for negative weights plus it's easier to implement - no priority queue or extra space complexity.

Hello from Canada! These videos are awesome and help me learn much better than my regular prof.

Great ! You are a great Teacher. Thanks for saving my Design and analysis of Algorithm Paper. #Respect

Thankyou from NIT Warangal

Guru Brahma guru Vishnu guru deva Maheshwara ,guru shakshat param bhrahma tasmayeshri gurudev namah ,.pranam sir , algorithms guru ji 🙏🙏deep respects sir

Very clean and to the point explanation. Thank you very much sir. You are such an inspiration.

you are saving my life.Thank you brother. Brother from different mother :)

Thanks Abdul! See you at England v Holland.

yahahaha my friends were telling me I would fail this subject because of those algorithms because I didn't attend the classes but thank god internet exist I will pass like a boss

Your videos are the best resources for my algorithm classes. Thank you very much

Thank you so much. Without a doubt the best video on this algorithm.

till 8:31 there was a mistake 4,2=8 instead of 8.....but corrected nice video

GOD !!!

Thank you sooo much sir, you made the complex algorithms much more easy and vivid to understand!

Thank you so much for producing this video. You just saved me hours and hours of time trying to go through the unclear explanation in the book (probably only to give up at the end).

Sir, There is a mistake in finding A1 A1=0 3 α 7 8 0 2 15 5 8 0 1 2 5 α 0 Can u check it sir....

Dijkstra takes O(ElogV). So, if we calculate using Dijkstra it would be O(n^3*logn)

Thanks, i have a computer science background, and this video is is helping me understand how the basic ideas are expressed mathematically for dynamic programming.

you sir are the teacher we all hoped to get when we joined our colleges

6:40,Correction A1 matrix (4,2) = 5

how you come up with this bro

love you sir. Lots of effort for easy understanding. Without your videos my MTECH would be a tragedy :) hats off

Best explanation for graph i have come across in any video!!

@13:55 isn't the time complexity again n^3 which we were trying to avoid initially??

you are my god, my lovely indian sir god

A big thank you from Ghana. You saved me a whole lot of time.

It got into my head very easily...love ur videos...much helpful in my studies..way to go sir.....keep posting....