归并排序

import random


def merge(mer_l, mer_r):
    new_list = []
    i = 0
    j = 0
    len_l = len(mer_l)
    len_r = len(mer_r)
    while len_l > i and len_r > j:
        if mer_l[i] < mer_r[j]:
            new_list.append(mer_l[i])
            i += 1
        else:
            new_list.append(mer_r[j])
            j += 1
    while i < len_l:
        new_list.append(mer_l[i])
        i += 1
    while j < len_r:
        new_list.append(mer_r[j])
        j += 1
    return new_list


def _merge_sort(li, low, mid, high):
    if high > low:
        _merge_sort(li, low, (low+mid)//2, mid)
        _merge_sort(li, mid+1, (mid+1+high)//2, high)
        li[low:high+1] = merge(li[low:mid+1], li[mid+1:high+1])


def merge_sort(li):
    high = len(li) - 1
    low = 0
    mid = (high + low)//2
    _merge_sort(li, low, mid, high)


if __name__ == '__main__':
    li3 = list(range(100))
    random.shuffle(li3)
    print(li3)
    merge_sort(li3)
    print(li3)