快速排序 用C语言

以下是使用C语言实现快速排序的代码：

#include <stdio.h>

// 单趟排序
int PartSort(int* arr, int begin, int end) {
    int key = arr[end];
    while (begin < end) {
        while (begin < end && arr[begin] <= key) {
            ++begin;
        }
        arr[end] = arr[begin];
        while (begin < end && arr[end] >= key) {
            --end;
        }
        arr[begin] = arr[end];
    }
    arr[end] = key;
    return end;
}

// 快速排序递归实现
void QuickSort(int* arr, int begin, int end) {
    if (begin >= end) {
        return;
    }
    int key = PartSort(arr, begin, end);
    QuickSort(arr, begin, key - 1);
    QuickSort(arr, key + 1, end);
}

// 快速排序非递归实现
void QuickSortNonRecursive(int* arr, int begin, int end) {
    int stack[end - begin + 1];
    int top = -1;
    stack[++top] = begin;
    stack[++top] = end;
    while (top >= 0) {
        int right = stack[top--];
        int left = stack[top--];
        int key = PartSort(arr, left, right);
        if (key - 1 > left) {
            stack[++top] = left;
            stack[++top] = key - 1;
        }
        if (key + 1 < right) {
            stack[++top] = key + 1;
            stack[++top] = right;
        }
    }
}

int main() {
    int arr[] = { 5, 3, 8, 4, 2, 7, 1, 6 };
    int len = sizeof(arr) / sizeof(arr[0]);
    QuickSort(arr, 0, len - 1);
    for (int i = 0; i < len; ++i) {
        printf("%d ", arr[i]);
    }
    printf("\n");
    QuickSortNonRecursive(arr, 0, len - 1);
    for (int i = 0; i < len; ++i) {
        printf("%d ", arr[i]);
    }
    printf("\n");
    return 0;
}