内部排序-快速排序

#include<iostream>
using namespace std;
#define MAX 100   //假定最大长度为100
#define OK 1
typedef int KeyType;  //假定数据类型为int
typedef struct {
	KeyType key;  //关键字项
}RedType;  //记录类型
typedef struct {
	RedType r[MAX + 1];  //r[0]用作哨兵
	int length;  //表长
}SqList;  //表的类型
int InitList_Sq(SqList& L);  //初始化顺序表
int Partition(SqList& L, int low, int high);
void QSort(SqList& L, int low, int high);  //快速排序
void print(SqList L);  //输出顺序表
int main()
{
	SqList L;
	InitList_Sq(L);
	QSort(L, 1, L.length);
	print(L);

	return 0;
}
int InitList_Sq(SqList& L)
{
	int n, k = 1;  //n为待输入数，k为计数器
	L.length = 0;  //表长初始化为0
	while (1)
	{
		cin >> n;
		if (n == -1)  //假设输入-1为结束标志
			break;
		L.r[k++].key = n;
		L.length++;  //表长+1
	}
	return OK;
}
int Partition(SqList& L, int low, int high)
{
    L.r[0] = L.r[low];  //设置哨兵位
    int pivotkey = L.r[0].key;  //设置中心元素
    while (low < high)
    {
        while (low < high && L.r[high].key >= pivotkey)  //从表尾开始找元素
            --high; //high向前移动
        L.r[low] = L.r[high];
        while (low < high && L.r[low].key < pivotkey)  //从表头开始找元素
            ++low; //low向后移动
        L.r[high] = L.r[low];
    }
    L.r[low] = L.r[0];
    return low;  //返回排序后中心元素的位置
}
void QSort(SqList& L, int low, int high)
{
    if (low < high)  //长度大于1
    {
        int pivotloc = Partition(L, low, high);  //设置枢轴位置
        QSort(L, low, pivotloc - 1);  //对低子表递归排序
        QSort(L, pivotloc + 1, high);  //对高子表递归排序
    }
}

void print(SqList L)
{
	for (int i = 1; i <= L.length; i++)
		cout << L.r[i].key << ' ';
	cout << endl;
}