All the fancy power points and drawing tablets and still the best explanation is a homie with paper cups. Thank you, sir!

I think it's funny how you don't use anything fancy to explain this, and yet your explanation is still one of the best.

This is the best video on Quicksort. However, at 4:05, we could just swap "Pivit" and the "i+1".

One of the most understanding videos i have seen so far about QuckSort. Thank you sir, extremely understanding

I watched your instruction twice, not because it's hard to understand but so enjoyable to watch. Thank you

not gonna lie, its the best video available for quicksort.

Usually I don't comment on video but I have to make an exception for this one because EVERYTHING WAS JUST PERFECTLY EXPLAINED.... It changes from the videos where the guy takes more than 10mn to explain it in a way that will confuse more KEEP IT UPP 🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥

this explains a lot why "i" started at index -1. Thanks.

I've never seen such an amazing teaching method, thank you! This is gold

This Legend is replying to comments even after 6 years.❤

This is the best explanation i've come across!

This is the best explanation of quicksort I've seen on youtube and using simple paper cups of all things.

possibly best video on KZfaq to understand Quicksort. Everyone just dry runs the algorithm - without clearly showing what's being done and why. You won 'em all!

you are very good at explaining this complex algorithm! with your calmness it was very easy to follow you step by step. you are the only one that actually helped me to understand :) Great job! Thank you!

This is a clear explanation, but I'd avoid shifting the array at 4:07 and just swap the 4 and the 8 (that is, the element at the pivot position with the element at i+1) since it's much less work and it will also result in guaranteeing what we need: everything to the left of i + 1 is smaller than the pivot, everything to the right of i+1 is greater than the pivot, and the pivot is at i.

Only after watching this video did I understand that the `i` only increments when a swap happens, in effect keeping track of where the pivot should finally rest. The best explanation I've seen on quicksort partitioning!

Amazing explanation! Thank you, Thank you, Thank you :) Very clearly explained and the visual aids were amazingly helpful.

this is by far the best explanation of quicksort so far after pouring through countless videos.

Incredibly helpful. Textbooks and online articles handwaved over partitioning. Thank you for explaining this so well.

This is amazing! Great explanation. I could not understand quicksort until you masterfully and elegantly demonstrated how the algorithm works.

One of the best explanations, you nailed it

this was the best explanation of Quicksort in youtube

The loveliest explanation of partitioning ever made. Hats off to you man!

Teacher took 40 mins. Book took 1 hour. This guy taught me in 10 mins.

Please, can someone give all the humans, animals and plants as subscribers to this legend

probably the best explanation of quick sort in so less time,one thing to say to understand this better you first go throuhh the video explain by mycodeschool channel and then watch this and you will see clearly how things are working here. Hats off you sir! Great job.....

Thank you prof KC Ang. After so many days of confusion I finally got clear explanation from your video. Thank you for virtually sharing your knowledges!!

It looks like this guy knows how to teach, awesome vid.

I find it really interesting how Quicksort as a sorting algorithm itself is intuitively quite simple but I've seen so many different methods for partitioning the array.

I've been searching like a hour for a clear explanation. Thank you! You are a life saver.

thank you for this video!! i love how you used the cups, it's so much easier seeing this happen in real life instead of a digital diagram/images on screen.

This is most certainly the easiest video to understand about partition. I literally am mad it's this easy haha!! Thank you so much!!! I definitely did NOT study this the day before my test :P

Best explanation ever. Very clear and crisp explanation and the representation helps to literally visualize the problem. Thank you !

thank you again, I have spent my day trying to learn quick sort and this video actually gave a clear understanding to a point I can implement code with no problem. Thank you !!!!

You are honestly good . Ur way is the best way to explain this, dunno why people keep explain this by code, all viewer want to know is the idea to do q sort ans you did it well

This is the most clear explanation I have ever seen of the algorithm. Thank you so much.

I wish our college lecture had explained it this clearly. College is where we go to get grades; KZfaq is where we come to learn. Thanks KC Ang.

I struggled fully grasping this concept of why this works, you explained it very well and made the click that when I look back I don't understand where my confusion came through. Thank you so much.

I went though so many videos. This is where I have understood the logic behind this algorithm very well. Thank you so much Master.

Amazing, short, easy explanation

This is the correct way every human being can get crystal clear understanding of hardest topic easily Respect to great teacher like you sir love & Respect from India

This is the best explanation of Partitioning on KZfaq. Thank you!

Agreed with previous person. The most clear description of Quicksort I've seen. Well done and thank you.

at the last step you should swap not shift ... shifting means moving all the next objects and that would be with no purpose ... but swapping does the work simply with no extra efforts

Very smart implementation Mr. Ang!

the best explanation of quick sort thank you

This is single handedly the best visualization of quicksort I've ever seen. Thanks for this!

It's amazing how much better this tutorial is than the other ones out there. Especially from a non-native English speaker. I applaud you.

Great explanation! One thing to mention is, instead of shifting everything from i+1 to the right, you can just do a swap of A[i+1] and pivot, (4 and 8 in this case) which is probably more efficient.

At 4:06 (when the partitioning is finished) there was a shift in the array which is very expensive, for the purpose of the quicksort I believe it'd be a more beneficial if you instead swapped the pivot with (i + 1)

you make so much sense, the hardest part of quick sort is understanding the first passing of the partitioning function. Thank you

thank u sir....this is the most clear explanation than most of other explanations of quick sort in the youtube.

The best explanation of partitioning I have ever seen.

he explains complex stuff in a very plain way. What an illustration!

I've been watching about 20 videos of quicksort, this is only one that explains the concept clearly

Thank you so much! This is the only explaination I can understand. No those fancy graphic animation and music, no confusing complex definition and pesudo code, just a straight forward visual explanation. After I watched this, the pesudo code suddenly makes sense now.

Watched so many quicksort videos but this one is the best. Thank you good sir !

Wow...the way you used the cups for explaning the concept is so creative

clever way of sorting the array and demonstrating how the i and j move through the loop together and make the pivot! Thank you so much for your efforts!!

You are an amazing instructor ... its is considered the best tutorial in quick sort algorithm

This is the best video on quick sort I have watched . Thanks man for making this amazing video.

OMG, your explanation makes a lot of sense compared to other videos i've seen, NOW I GET IT>>>>>>>>>>>>>>>> THANKS

This is the best explanation of Quicksort I 've come across anywhere. Cheers

He explained in 5 minutes what other videos didn’t in 10-15 minutes. Best quicksort video I’ve seen

I finally understood QuickSort(A[],first,last). Thank you very much. You video was very illuminating!

The kind of teachers we students crave for!!....Thanks Sir

You're great sir. I was trying to understand quick sort from many days, but you made me understand the working of quick sort partition in less than 5 minutes. Thank you so much.

The video describes the basic unit of computation in the processing of quick sort algorithm. Very clear and beautiful!

Best video I've seen yet... keep up the good work!

Best explanation ever of quicksort

So simple and elegant, straight to the point. Much better than those overdone graphics you see in other channels.

I surprised that so many people in KZfaq do not understand how the quicksort works even if they post the video about it. Except for him. great video.

Finally I know how QuickSort works. Thank you.

Just Awesome !!!! Crystal Clear !! Tried a few lectures! This is GOLD! 👍❤️

I believ i see your video everytime i need to refresh about quick sort. Thank you. I may have seen it more than 15 times !

WOW, I MEAN WOW. This is the best explanation of the QuickSort I have seen. Not even AI help could have shown that. Thank you.

The best example I have seen on the internet. Thank you Sir

This is the first explanation that I understand immediately after I've watched it! Thank you so much! Greetings from Hungary :)

I'm crying, you have successfully beaten my top ranked uni professors. Perfect explanation

7 years on and still this is the best

Very clear explanation! Wish all of my proffessors had this impact

Great video, thank you so much. The book and examples made no sense, but this is a lot better than the examples online.

very clear! having i j and r and pivot on top of the cups really helped compared to other videos...

After going through so many contents and KZfaq videos I finally found someone explaining the Quicksort in a very clear manner. Brilliant job KC...!👌

Amazing explanation!

Some more information for those coming here. This particular method, of taking the pivot as the last element, is known as the Lomuto Partition scheme. There are other partition schemes, that slightly alter the flow and complexity of the quick sort algorithm. Also, the process shown in the video has one problem, if the first element is less than the pivot the algorithm fails. This is easily solvable, just make the few changes below: 1. I and J in the beginning point to the same element. 2. If an element is less than pivot, I and J interchange, and then I is incremented, which if it happens in the first instance, means the first element is replaced by the first itself. No change. 3. J increments normally. And finally, just swap the elements of the pivot and the final value of I, no shifting. This saves time. Just swap 7 and 2 in the beginning, or add any number itself to the array, less than 4, and try it out.

He is probably the simplest man on internet! Thanks man! appreciate it.

Was having a lot of trouble understanding this algorithm until I stopped here and watched your video - now it totally makes sense! Thank you for taking the time to not only make the video, but to actually demonstrate the algorithm in physical form. It really helped me to learn much more concretely than any of the code snippets other tutorials were relying on.

This is the best video on Quicksort

Thank you so much, my prof. didnt explain it as good as u did, i was really confused about the pivot before.

definitely the best explanation to be found on youtube. Thank you!

best explanation of the algorithm, cleared my confusion in minutes. thank you!!

Thanks for posting this. I found it enormously helpful.

I have to admit there is a lot of great videos out there for data structure and sorting videos, but loved this one!

Wow! What a great instructor. This is brilliant. Thank you so much for the amazing explanation.

The best part was that you actually pointed me to the fact the (i) pointer is initially at (low -1) and that it will not be out of bound because it will be incremented just before the first swap. Special thanks for that.

First video of 5 that actually made sense

Best explanation ever.

WOW, I watched green animation video, and was giving up on quick sort, and then watched your video and its as clear as day.

One of the best simulations of the partition procedure, thanks for making this video :) I hope to see more of your video. Thanks