Function merge_sort

code/all_sort.py:13–19

(arr1)

# 归并
def merge_sort(arr1):
    if len(arr1) < 2:
        return arr1
    half = int(len(arr1) / 2)
    left_arr1 = merge_sort(arr1[:half])
    right_arr1 = merge_sort(arr1[half:])
    return merge(left_arr1, right_arr1)

def merge(left, right):
    result = []