八大排序算法的python实现

# -*- coding: utf-8 -*-# 冒泡排序def bubble_sort(nums):    i = 1    exchanged = True    while i < len(nums) and exchanged:        exchanged = False        for j in range(len(nums) - i):            if nums[j] > nums[j + 1]:                nums[j], nums[j + 1] = nums[j + 1], nums[j]                exchanged = True        i += 1    return nums# 快速排序def quick_sort(nums, left=0, right=None):    if right == None:        right = len(nums) - 1    if left >= right:        return nums    low = left    high = right    key = nums[left]    while left < right:        while left < right and nums[right] >= key:            right -= 1        nums[left], nums[right] = nums[right], nums[left]        while left < right and nums[left] <= key:            left += 1        nums[left], nums[right] = nums[right], nums[left]    quick_sort(nums, low, left - 1)  # 递归    quick_sort(nums, right + 1, high)  # left == right    return nums# 插入排序def insert_sort(nuns):    for i in range(1, len(nums)):        key = nums[i]        i -= 1        while i >= 0 and nums[i] > key:            nums[i + 1] = nums[i]            i -= 1        nums[i + 1] = key    return nums# 希尔排序def shell_sort(nums):    gap = len(nums) // 2  # 初始增量，//整除    while gap > 0:        # 缩小增量，直至增量为1        for i in range(0, gap):            # 分组            j = i + gap            while j < len(nums):                # 组内插入排序                key = nums[j]                k = j - gap                while k >= 0 and nums[k] > key:                    nums[k + gap] = nums[k]                    k -= gap                nums[k + gap] = key                j += gap        gap //= 2    return nums# 选择排序def select_sort(nums):    for i in range(len(nums)):        minimum = i        for j in range(i + 1, len(nums)):            if nums[j] < nums[minimum]:                minimum = j        nums[i], nums[minimum] = nums[minimum], nums[i]    return nums# 堆排序def max_heapify(nums, i, size):    # 最大堆调整    # 注意数组的size比数组的最大索引大1    lchild = 2 * i + 1    rchild = 2 * i + 2    maximum = i    if i < size // 2:        if nums[lchild] > nums[maximum]:            maximum = lchild        if rchild < size:            # 肯定有左子节点，未必有右子节点            if nums[rchild] > nums[maximum]:                maximum = rchild        if maximum != i:            nums[i], nums[maximum] = nums[maximum], nums[i]            max_heapify(nums, maximum, size)  # 递归def build_max_heap(nums, size):    # 创建最大堆    for i in range(size // 2 - 1, -1, -1):        max_heapify(nums, i, size)def heap_sort(nums):    size = len(nums)    build_max_heap(nums, size)    for i in range(1, size):        nums[0], nums[size - i] = nums[size - i], nums[0]        max_heapify(nums, 0, size - i)    return nums# 归并排序def merge_sort(nums):    length = len(nums)    if length <= 1:        return nums    list1 = merge_sort(nums[: length // 2])    list2 = merge_sort(nums[length // 2:])  # 递归    i = 0    j = 0    k = 0    while i < len(list1) and j < len(list2):        if list1[i] < list2[j]:            nums[k] = list1[i]            i += 1            k += 1        else:            nums[k] = list2[j]            j += 1            k += 1        nums = nums[: k] + list1[i:]        nums = nums[: k] + list2[j:]  # 其中一个为空列表    return nums# 基数排序def radix_sort(nums):    maximum = nums[0]    for num in nums:        # 找到最大值        if num > maximum:            maximum = num    k = 1    while maximum // (10 ** k) > 0:        # 判定最大值是几位数        k += 1    for i in range(k):        buckets = [[] for x in range(10)]        for num in nums:             buckets[(num // (10 ** i)) % 10].append(num)        nums = []        for b in buckets:            nums += b    return nums# 测试nums0 = list(range(200))nums = list(range(200))random.shuffle(nums)print(bubble_sort(nums) == nums0)print(quick_sort(nums) == nums0)print(insert_sort(nums) == nums0)print(shell_sort(nums) == nums0)print(select_sort(nums) == nums0)print(heap_sort(nums) == nums0)print(merge_sort(nums) == nums0)print(radix_sort(nums) == nums0)