请大家看一下错在哪里了【快速排序实现报错】

Question

麻烦大家看一下，按照书上实现的快速排序，但一直输出的是排序前，这是为什么呢？应该该怎么修改呢？谢谢！

#include<iostream>
using namespace std;


typedef struct
{
    int key1;
    int key2;
}Data;

typedef struct 
{
    Data *r = NULL;
    int length;
}SqList;

int point;


int Partition(SqList &L, int low, int high)
{
    L.r[0] = L.r[low];
    point = L.r[low].key1;
    while (low < high)
    {
        while (low < high && L.r[high].key1 >= point)
        {
            --high;
        }
        L.r[low] = L.r[high];

        while (low < high && L.r[low].key1 <= point)
        {
            ++low;
        }
        L.r[high] = L.r[low];

    }
    L.r[low] = L.r[0];
    return low;
}

void QSort(SqList &L, int low, int high)
{
    if (low < high)
    {
        point = Partition(L, low, high);
        QSort(L, low, point - 1);
        QSort(L, point + 1, high);
    }
    for (int i = 0; i < 5; i++)
    {
        cout << L.r[i].key1;
    }

}


int main(void)
{
    SqList L;
    L.r = new Data[10];
    for (int i = 0; i < 5; i++)
    {
        cin >> L.r[i].key1;
    }
    QSort(L, 1, L.length);
    delete[] L.r;
        return 0；
}

Answer 1

在main函数中第61行未对L.length进行初始化，因此会导致程序出现未定义的行为。可以在代码的开头定义L的初始化语句

SqList L = {new Data[10], 5};