Quicksort 1 – The Algorithm

This video describes the principle of the QuickSort. The quick sort is a divide and conquer algorithm which sorts a list by selecting a pivot value from the list, then placing other items on either side of the pivot depending on whether they are bigger or smaller. This results in three partitions with the pivot in the correct place. This partitioning process is repeated for each partition generated, until every partition contains only one item, each of which is in the correct place. This video also includes descriptions of two different versions of pseudocode for the quick sort algorithm.

[xF]

During my two years at A level we had a replacement teacher who wasn't able to teach us the more mathematical and algorithmic side of the course. Your videos have saved me just in time for my exams, thank you.

[alenavass]

You are honestly so good at explaining clearly while keeping it concise. Thank you!

[ThePandaGuitar]

Please keep teaching Kevin! This is YouTube gold!

[abz]

OH my god this is the best explanation ever the other vids are so bad compared to this

[yvbuzan]

thank you for this wonderful video. I like it very much.

[prabhakarpalanivel]

Good one Kevin, one minor suggestion, in terms of coding it, its slightly vague. It might have been clearer if we keep swapping the values when array[L] > pivot and array[R] < pivot which i think was the original quick-sort algorithm (which evolved subsequently)

[AmNotLegend]

maybe not exactly correct, 9:15 then losing the data[LeftPointer]

[jtlunsford]

How many items to sort, where QuickSort becomes more efficient than Bubble and Insertion? It's a good sort, but I can see, or at least I think I see an easier way. I'd have to play with it and I'm sure I'm not the first to think that. Anyway, on to the next vid and you make it so simple, but I'm still going to mull the pseudocode over in my tiny little brain...LOL Thanks so much for all this learning opportunity you provide. I always read the comments, and everyone agrees, U Da Man....JT

[rollyrodrigz]

Mr, awesome tutorials. Would you like to make videos solving algorithms problems?. For example algorithms from hackerrank.