先写上代码，过后再补

#include<iostream>
#include<stack>
using namespace std;

//一趟快排排序
int sort(int num[], int low, int high)
{
    int n = 8;
    int pivotkey = num[low];
    while (low < high)
    {
        while (low < high&&num[high] >= pivotkey)
        {
            --high;
        }
        num[low] = num[high];
        while (low < high&&num[low] <= pivotkey)
        {
            ++low;
        }
        num[high] = num[low];
    }
    num[low] = pivotkey;
    for (int i = 0; i < n; ++i)
    {
        cout << num[i] << " ";
    }
    cout << endl;
    cout << low << " " << high << endl;
    return low;
}

//递归调用
void recursion(int num[], int low, int high)
{
    if (low < high)
    {
        int pivotkey = sort(num, low, high);
        recursion(num, low, pivotkey - 1);
        recursion(num, pivotkey + 1, high);
    }
}

//非递归调用
void storenum(int num[], int low, int high) 
{
    stack<int> st;
    if (low < high)
    {
        int mid = sort(num, low, high);
        if (low < mid - 1)
        {
            st.push(low);
            st.push(mid - 1);
        }
        if (mid + 1 < high)
        {
            st.push(mid + 1);
            st.push(high);
        }
        while (!st.empty())
        {
            int q = st.top();
            st.pop();
            int p = st.top();
            st.pop();
            mid = sort(num, p, q);
            if (p < mid - 1)
            {
                st.push(p);
                st.push(mid - 1);
            }
            if (mid + 1 < q)
            {
                st.push(mid + 1);
                st.push(q);
            }
        }
    }
}

int main()
{
    int num[8] = { 49,38,65,97,76,13,27,49 };

    //快速排序的递归算法
    recursion(num, 0, 7);
    for (int i = 0; i < 8; ++i)
    {
        cout << num[i] << " ";
    }

    //快速排序的非递归算法
    //storenum(num, 0, 7);
    //for (int i = 0; i < 8; ++i)
    //{
    // cout << num[i] << " ";
    //}
    return 0;
}