05_归并排序

def merge_sort(data):

    '''

    归并排序

    :param lists:

    :return:

    '''

    num = len(data)

    if num <= 1:

        return data

    mid = num // 2

    left = merge_sort(data[:mid])

    right = merge_sort(data[mid:])

    return merge(left, right)

def merge(left,right):

    r, l = 0, 0

    result = []

    while l < len(left) and r < len(right):

        if left[l] <= right[r]:

            result.append(left[l])

            l += 1

        else:

            result.append(right[r])

            r += 1

    result += list(left[l:])

    result += list(right[r:])

    return result