常见排序算法的python实现

以下代码实现的排序算法有：选择排序，冒泡排序，插入排序，希尔排序，归并排序，快速排序

# -*- coding:utf-8 -*-
li = [23, 12, 43, 45, 54, 514, 412, 543, 123, 534, 675, 1232]


def select_sort(li):
    # 选择排序
    for i in range(len(li)):
        for j in range(i, len(li)):
            if li[i] > li[j]:
                li[i], li[j] = li[j], li[i]
    return li


print(select_sort(li))


def bubble_sort(li):
    # 冒泡排序
    for i in range(len(li)):
        for j in range(1, len(li) - i):
            if li[j] < li[j - 1]:
                li[j], li[j - 1] = li[j - 1], li[j]
    return li


print(bubble_sort(li))


def insert_sort(li):
    # 插入排序
    for i in range(1, len(li)):
        key = li[i]
        j = i - 1
        while j >= 0:
            if key < li[j]:
                li[j + 1] = li[j]
                li[j] = key
            j -= 1
    return li


print(insert_sort(li))


def shell_sort(li):
    # 希尔排序
    gap = len(li) % 2
    while gap > 0:
        for i in range(gap, len(li)):
            if li[i] < li[i - gap]:
                li[i - gap], li[i] = li[i], li[i - gap]
    return li


print(shell_sort(li))


def merge_sort(l1, l2):
    # 归并排序
    l3 = []
    j = 0
    for i in range(len(l1)):
        while j < len(l2) and l1[i] > l2[j]:
            l3.append(l2[j])
            j += 1
        l3.append(l1[i])
    if j < len(l2) - 1:
        while j < len(l2):
            l3.append(l2[j])
            j += 1
    return l3


list1 = [1, 3, 5, 7, 9]
list2 = [2, 4, 6, 8, 10, 11, 12, 13, 14]
print(merge_sort(list1, list2))


def quick_sort(li, start, end):
    # 快速排序
    if start < end:
        index = kp(li, start, end)
        quick_sort(li, index +1, end)
        quick_sort(li, start, index)
    return li


def kp(li, start, end):
    # 快速排序用来排序的函数
    base = li[start]
    while start < end:
        while base <= li[end] and start < end:
            end -= 1
        while start < end and base > li[end]:
            li[start], li[end] = li[end], li[start]
            start += 1
    return start


print(quick_sort(li, 0, len(li) - 1))