一直进步 做喜欢的

排序算法是一种将一组元素按照特定规则进行排列的算法。tips：

• 稳定指如果a原本在b前面，而a=b，排序之后a仍然在b的前面。
• 二维数组.sort(key=lambda x: x[0]) 根据指定二维数组的第一个元素升序排序
• 二维数组.sort(key=lambda x: (x[0], -x[1]))根据指定二维数组的第一个元素升序排序，若第一个元素相等，按第二个元素降序排序
• sort()排序的时间复杂度为O(NlogN)，使用的是归并排序。

# 冒泡排序
def bubble_sort(arr):
    n = len(arr)
    for i in range(n - 1):
        for j in range(n - 1 - i):
            if arr[j] > arr[j + 1]:
                arr[j], arr[j + 1] = arr[j + 1], arr[j]
    return arr

# 插入排序
def insertion_sort(arr):
    n = len(arr)
    for i in range(1, n):
        key = arr[i]
        j = i - 1
        while j >= 0 and arr[j] > key:
            arr[j + 1] = arr[j]
            j -= 1
        arr[j + 1] = key
    return arr

# 选择排序
def selection_sort(arr):
    n = len(arr)
    for i in range(n - 1):
        min_index = i
        for j in range(i + 1, n):
            if arr[j] < arr[min_index]:
                min_index = j
        arr[i], arr[min_index] = arr[min_index], arr[i]
    return arr

# 快速排序
def quick_sort(arr):
    if len(arr) <= 1:
        return arr
    pivot = arr[0]
    left = [x for x in arr[1:] if x <= pivot]
    right = [x for x in arr[1:] if x > pivot]
    return quick_sort(left) + [pivot] + quick_sort(right)


# 归并排序
def merge_sort(arr):
    if len(arr) <= 1:
        return arr
    mid = len(arr) // 2
    left = merge_sort(arr[:mid])
    right = merge_sort(arr[mid:])
    return merge(left, right)

def merge(left, right):
    merged = []
    i = j = 0
    while i < len(left) and j < len(right):
        if left[i] <= right[j]:
            merged.append(left[i])
            i += 1
        else:
            merged.append(right[j])
            j += 1
    while i < len(left):
        merged.append(left[i])
        i += 1
    while j < len(right):
        merged.append(right[j])
        j += 1
    return merged


# 堆排序
def heapify(arr, n, i):
    largest = i
    left = 2 * i + 1
    right = 2 * i + 2

if left < n and arr[left] > arr[largest]:
        largest = left

if right < n and arr[right] > arr[largest]:
        largest = right

if largest != i:
        arr[i], arr[largest] = arr[largest], arr[i]
        heapify(arr, n, largest)

def heap_sort(arr):
    n = len(arr)

for i in range(n // 2 - 1, -1, -1):
        heapify(arr, n, i)

for i in range(n - 1, 0, -1):
        arr[i], arr[0] = arr[0], arr[i]
        heapify(arr, i, 0)

return arr


# 希尔排序
def shell_sort(arr):
    n = len(arr)
    gap = n // 2

while gap > 0:
        for i in range(gap, n):
            temp = arr[i]
            j = i
            while j >= gap and arr[j - gap] > temp:
                arr[j] = arr[j - gap]
                j -= gap
            arr[j] = temp
        gap //= 2

return arr

十大经典排序算法（动图演示）