【Python】排序你学废了吗，茴香豆有四种写法，排序有十种写法

1. 冒泡排序

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

2. 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 key < arr[j]:
            arr[j+1] = arr[j]
            j -= 1
        arr[j+1] = key
    return arr

3. 选择排序

def selection_sort(arr):
    n = len(arr)
    for i in range(n-1):
        min_idx = i
        for j in range(i+1, n):
            if arr[j] < arr[min_idx]:
                min_idx = j
        arr[i], arr[min_idx] = arr[min_idx], arr[i]
    return arr

4. 快速排序

def quick_sort(arr):
    if len(arr) <= 1:
        return arr
    pivot = arr[len(arr) // 2]
    left = [x for x in arr if x < pivot]
    middle = [x for x in arr if x == pivot]
    right = [x for x in arr if x > pivot]
    return quick_sort(left) + middle + quick_sort(right)

5. 归并排序

def merge_sort(arr):
    if len(arr) <= 1:
        return arr
    mid = len(arr) // 2
    left = arr[:mid]
    right = arr[mid:]
    left = merge_sort(left)
    right = merge_sort(right)
    return merge(left, right)
    
def merge(left, right):
    result = []
    i = j = 0
    while i < len(left) and j < len(right):
        if left[i] < right[j]:
            result.append(left[i])
            i += 1
        else:
            result.append(right[j])
            j += 1
    result += left[i:]
    result += right[j:]
    return result

6. 堆排序

def heapify(arr, n, i):
    largest = i
    l = 2 * i + 1
    r = 2 * i + 2
    if l < n and arr[l] > arr[largest]:
        largest = l
    if r < n and arr[r] > arr[largest]:
        largest = r
    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

7. 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

8. 计数排序

def counting_sort(arr):
    n = len(arr)
    max_val = max(arr) + 1
    count = [0] * max_val
    for i in range(n):
        count[arr[i]] += 1
    for i in range(1, max_val):
        count[i] += count[i-1]
    output = [0] * n
    for i in range(n-1, -1, -1):
        output[count[arr[i]]-1] = arr[i]
        count[arr[i]] -= 1
    return output

9. 桶排序

def bucket_sort(arr):
    n = len(arr)
    max_val = max(arr) + 1
    bucket = [[] for _ in range(n)]
    for i in range(n):
        index = arr[i] * n // max_val
        bucket[index].append(arr[i])
    for i in range(n):
        bucket[i].sort()
    output = []
    for i in range(n):
        output += bucket[i]
    return output

10. 基数排序

def radix_sort(arr):
    max_val = max(arr)
    exp = 1
    while max_val // exp > 0:
        arr = counting_sort_by_digit(arr, exp)
        exp *= 10
    return arr

def counting_sort_by_digit(arr, exp):
    n = len(arr)
    max_val = max(arr) // exp
    count = [0] * 10
    for i in range(n):
        index = (arr[i] // exp) % 10
        count[index] += 1
    for i in range(1, 10):
        count[i] += count[i-1]
    output = [0] * n
    for i in range(n-1, -1, -1):
        index = (arr[i] // exp) % 10
        output[count[index]-1] = arr[i]
        count[index] -= 1
    return output

茴香豆有四种写法，排序有十种写法，你学废了嘛~~~