Quick Sort – Computerphile | Nội Dung về chủ đề quick sort |

Thanks

Best explanation of the recursive nature behind the quicksort algorithm that I've found so far on YouTube. Thx well done.

The best quicksort tutorial

So merge sort is faster on average?

So it's a less stupid Mergesort?

in what scenario would one prefer quicksort to merge sort? What is the purpose of quicksort if merge sort exists?

Thank you! Now I can sort my books more easily

You keep using green as if it was your favorite color much more than any other!

Such a simple explanation! Thanks!

Best explanation of quicksort I have found.

So quicksort is basically merge sort except that the pivot point is chosen arbitrarily rather than to be always the middle?

Once, when I was young and designing sorting for a biology professor, to sort out his research data (ant populations) I took the most acclaimed sorting algorithm, quicksort at the time and wrote it into the program. And it promptly crashed due to stack overflow. Ok, it was back in the days of PC XT:s when both memory and stack were available in very limited supply. I switched to an non-recursive algorithm shellsort, which was quite sufficient. Problem solved.

Anyway, even later when the computer memory and stack were available in much larger chunks, I found out that the theoretically superior (recursive! Ooh how sexy) algorithm is not necessarily the fastest one in real world situations. I clocked both algorithms on real data. I was writing programs for real people doing real work, not for a theoretical situation. So I mostly shunned quicksort and used shellsort or mergesort instead.

Yes, the real-life situations are often like this: you have tens or hundreds of thousands of records (or millions) that are already sorted, and you want to add some additional elements (in the order of tens or hundreds) to these.

I've been watching a lot of these sorting algorithms and I can't understand why they have to do so many passes. Let's say we have 10 cards, I could create 10 boxes and on the first pass put 1s in the first pile, 2s in the second pile and so on then join them all together. In other example I have seen 15,000 integers sorted using quick sort, couldn't you just have an array with 15,000 keys then place the integer in the correct array?

really nice and simple explanation! 😀 thanks

This helped me out. Thanks!