Week 11 - Sorting and Efficiency

Actually, the topic about several ways to sort a list and their efficiency was discussed when i was learning CSC108. These weeks' lectures and labs let me get familiar with some more advanced sorting codes. The select sort is just like the one i learnt in 108 lecture and the efficiency was quite low. The quick sort and the merge sort can work much more efficiently; for example, in a case of sorting 1000-length list, these two are 10 times faster than select sort. One thing which is a little interesting is that if you want to sort a sorted list with quick sort, you will spend long time on it. It looks weird, but after analyzing the codes, i understand that the time spend on sorting is depend on the choice of pivot; so, if you choose the first item as pivot, the program will go through the list one by one which make that weird thing happen. I feel very excited about built-in sort, because it works so fast even if the length of random list is over 1000000. However, the count sort introduced by professor can defeat built-in way, if the length keeping growing, but it is a kind of trick which can not be used in general case. I do not know how built-in sort works, but Well, that is why built-in sort is built in.