"Python Learning notes-data structures and algorithms" merge sort

"Merge Sort" Here we use recursive algorithm to keep the list in two, base case is no element in the list or only one element, because this sub-list is bound to be a positive sequence, and then gradually merge the two sorted sub-list into a new positive sequence table, until all the elements sorted.

"This is a process from the bottom up (bottom-up)

Divides the list from the middle into two sub-lists until it reaches the bottom, with only one element in the sub-list

　　

Then, the two sub-lists are merged from bottom to top, and all the elements of the two sub-lists are sorted to form a new list.

　　

"Implementation of merge Sort"

　　

You can use print to see what you've done with each step.

"Performance Analysis"

The time complexity is O (n*log N), but the merging process requires extra space and the space complexity is O (n).

"Python Learning notes-data structures and algorithms" merge sort