十大排序算法PYTHON

十大排序算法是指在数据结构与算法领域中，一些常用的、高效的排序方法。在Python中实现这些算法通常非常直观和简洁。以下是十大排序算法及其在Python中的简单实现示例：

1. 冒泡排序（Bubble Sort）

def bubble_sort(arr):
    n = len(arr)
    for i in range(n):
        for j in range(0, n-i-1):
            if arr[j] > arr[j+1]:
                arr[j], arr[j+1] = arr[j+1], arr[j]

2. 选择排序（Selection Sort）

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

3. 插入排序（Insertion Sort）

def insertion_sort(arr):
    for i in range(1, len(arr)):
        key = arr[i]
        j = i-1
        while j >=0 and key < arr[j]:
            arr[j+1] = arr[j]
            j -= 1
        arr[j+1] = key

4. 希尔排序（Shell Sort）

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

5. 归并排序（Merge Sort）

def merge_sort(arr):
    if len(arr) > 1:
        mid = len(arr) // 2
        L = arr[:mid]
        R = arr[mid:]

        merge_sort(L)
        merge_sort(R)

        i = j = k = 0
        while i < len(L) and j < len(R):
            if L[i] < R[j]:
                arr[k] = L[i]
                i += 1
            else:
                arr[k] = R[j]
                j += 1
            k += 1

        while i < len(L):
            arr[k] = L[i]
            i += 1
            k += 1

        while j < len(R):
            arr[k] = R[j]
            j += 1
            k += 1

6. 快速排序（Quick Sort）

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)

7. 堆排序（Heap Sort）

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

8. 计数排序（Counting Sort）

def counting_sort(arr, exp):
    n = len(arr)
    output = [0] * n
    count = [0] * (10**exp)
    for i in range(n):
        index = arr[i] // exp
        count[index % 10**exp] += 1
    for i in range(1, 10**exp):
        count[i] += count[i - 1]
    i = n - 1
    while i >= 0:
        output[count[arr[i] // exp] - 1] = arr[i]
        count[arr[i] // exp] -= 1
        i -= 1
    for i in range(len(arr)):
        arr[i] = output[i]

9. 桶排序（Bucket Sort）

def bucket_sort(arr):
    buckets = [[] for _ in range(len(arr))]
    for i in range(len(arr)):
        bucket = int(arr[i] * len(buckets))
        buckets[bucket].append(arr[i])
    for i in range(len(buckets)):
        buckets[i] = sorted(buckets[i])
    return [x for bucket in buckets for x in bucket]

10. 基数排序（Radix Sort）

def radix_sort(arr):
    max_value = max(arr)
    exp = 1
    while max_value // exp > 0:
        counting_sort(arr, exp)
        exp *= 10

这些排序算法在Python中的实现都非常直观，但在实际应用中可能需要根据数据的特性和使用场景来选择最合适的排序算法，以达到最优的性能。