归并算法

def merge(lst):
    m = len(merge)
    if m <= 1:
        return lst
    mid = m // 2
    left = merge(lst[:mid])
    right = merge(lst[mid:])
    return merge_sort(left, right)


def merge_sort(left, right):
    i, j = 0, 0
    result = []
    while i < len(left) and j < len(right):
        if left[i] < right[j]:
            result.append(left[i])
            i += 1
        else:
            result.append(right[j])
            j += 1
    result += left[i:]
    result += right[j:]
    return result