编辑代码

#include <iostream>

void quick_sort(int q[], int l, int r)
{
    //递归的终止情况
    if(l >= r) return;

    //第一步：分成子问题
    int i = l - 1, j = r + 1, x = q[l + r >> 1];
    while(i < j)
    {
        do i++; while(q[i] < x);
        do j--; while(q[j] > x);
        if(i < j) std::swap(q[i], q[j]);
    }

    //第二步：递归处理子问题
    quick_sort(q, l, j), quick_sort(q, j + 1, r);

}

int main() {
    int arr[] = {12, 7, 11, 5, 6, 13, 6};
    int n = sizeof(arr)/sizeof(int);

    std::cout << "Original array: ";
    for (int i : arr) {
        std::cout << i << " ";
    }

    quick_sort(arr, 0, n - 1);

    std::cout << "\nSorted array: ";
    for (int i : arr) {
        std::cout << i << " ";
    }

    return 0;
}