python快速排序和堆排

# coding=utf-8


def quick_sort(arr, start, end):
    if start >= end:
        return
    left = start
    right = end
    pivotkey = arr[start]
    while left < right:
        while left < right and arr[right] >= pivotkey:
            right -= 1
        arr[left] = arr[right]
        while left < right and arr[left] <= pivotkey:
            left += 1
        arr[right] = arr[left]

    arr[left] = pivotkey
    quick_sort(arr, start, left-1)
    quick_sort(arr, right + 1, end)


if __name__ == "__main__":
    test_list = [2, 10, 11, 6, 19, 21]
    quick_sort(test_list, 0, len(test_list)-1)
    print(test_list)

 

堆排序：

# coding=utf-8
import math


def print_tree(array):
    """
    将列表打印成堆
    :param array:
    :return:
    """
    index = 1
    depth = math.ceil(math.log2(len(array)))  # 因为补0了，不然应该是math.ceil(math.log2(len(array)+1))
    sep = '  '
    for i in range(depth):
        offset = 2 ** i
        print(sep * (2 ** (depth - i - 1) - 1), end='')
        line = array[index:index + offset]
        for j, x in enumerate(line):
            print("{:>{}}".format(x, len(sep)), end='')
            interval = 0 if i == 0 else 2 ** (depth - i) - 1
            if j < len(line) - 1:
                print(sep * interval, end='')
        index += offset
        print()


def heap_sort(arr):

    def max_heapify(root_index, end_index):
        # 减一因为堆的下标从1开始
        max_child_index = root_index*2-1

        # 有两个子节点的情况下， 比较两个子节点的大小
        if max_child_index + 1 < end_index:
            if arr[max_child_index+1] > arr[max_child_index]:
                max_child_index += 1

        # 将最大的子节点与根节点比较
        if arr[max_child_index] > arr[root_index-1]:
            arr[max_child_index], arr[root_index-1] = arr[root_index-1], arr[max_child_index]

    for end_index in range(len(arr), 1, -1):
        max_root_index = end_index // 2
        for root_index in range(max_root_index, 0, -1):
            max_heapify(root_index, end_index)

        # 调换根节点和末节点
        arr[0], arr[end_index-1] = arr[end_index-1], arr[0]


if __name__ == "__main__":
    arr = [0, 74, 73, 59, 72, 64, 69, 43, 36, 70, 61, 4, 0, 16, 47, 67, 17, 31, 19, 24, 14, 20, 48, 5, 7, 3, 78, 84, 92, 97, 98]
    print(arr)
    print_tree(arr)
    heap_sort(arr)
    print("---------------" * 10)
    print(arr)
    print_tree(arr)