python排序算法

二分法查找

def binary_search(nums, target):
    """
    :type nums: List[int]
    :type target: int
    :rtype: int
    """
    l, r = 0, len(nums)-1
    while l <= r:
        mid = (l + r) // 2
        if nums[mid] > target:
            r = mid - 1
        elif nums[mid] < target:
            l = mid + 1
        else:
            return mid
    return -1

快速排序

def q_sorted(lst):
    if len(lst) < 2:
        return lst
    pivot = lst[0]
    small, medium, large = [], [], []
    for item in lst:
        if item < pivot:
            small.append(item)
        elif item > pivot:
            large.append(item)
        else:
            medium.append(item)
    return q_sort(small) + medium + q_sort(large)

冒泡排序

def bubble_sorted(lst):
    l = list(lst)
    for i in range(len(l)-1):
        flag = True
        for j in range(len(l)-1-i):
            if l[j] > l[j+1]:
                l[j], l[j+1] = l[j+1], l[j]
                flag = False
        if flag:
            return l
    return l

选择排序

def select_sorted(lst):
    l = lst[:]
    for i in range(len(l)-1):
        min = i
        for j in range(i+1, len(l)):
            if l[j] < l[min]:
                min = j
        l[i], l[min] = l[min], l[i]
    return l

插入排序

def insert_sorted(lst):
    l = lst[:]
    for i in range(1, len(l)):
        value = l[i]
        index = i
        for j in range(i-1, -1, -1):
            if l[j] > value:
                l[j+1] = l[j]
                index = j
            else:
                break
        l[index] = value
    return l