快排,冒泡,插入,二分

import random

# 二分
def binary_search(li, val):
    low = 0
    high = len(li)-1
    while low <= high:
        mid = (low + high) // 2
        if li[mid] < val:
            low = mid + 1
        elif li[mid] > val:
            high = mid - 1
        else:
            return mid
    return None

# 快排

def partition(li, left, right):
    i = random.randint(left, right)
    li[left], li[i] = li[i], li[left]

    tmp = li[left]
    while left < right:
        # 从右边找比tmp小的数
        while left < right and li[right] >= tmp:
            right -= 1
        li[left] = li[right]
        # 从左边找比tmp大的数
        while left < right and li[left] <= tmp:
            left += 1
        li[right] = li[left]
    li[left] = tmp
    return left


def _quick_sort(li, left, right):
    if left < right:    # 表示至少两个元素
        mid = partition(li, left, right)
        _quick_sort(li, left, mid-1)
        _quick_sort(li, mid+1, right)

# li = list(range(100))
# random.shuffle(li)
# _quick_sort(li, 0, len(li)-1)
# print(li)

# 冒泡
def bubble_sort(li):
    for i in range(len(li)-1):  # i表示第i趟,共n-1趟
        # 第i趟 无序区范围 0~n-i-1
        for j in range(len(li)-i-1): # j表示箭头
            if li[j] > li[j+1]:
                li[j], li[j+1] = li[j+1], li[j]

# li = list(range(100))
# random.shuffle(li)
# bubble_sort(li)
# print(li)

# 插入
def insert_sort(li):
    for i in range(1, len(li)):
        # i 表示趟数 还表示摸到牌的位置
        j = i - 1
        tmp = li[i]
        while j >= 0 and li[j] > tmp:
            # 两个终止条件： 1. j==-1 2. j位置的值小于等于tmp
            li[j+1] = li[j]
            j -= 1
        li[j+1] = tmp

# li = list(range(100))
# random.shuffle(li)
# insert_sort(li)
# print(li)