快速排序算法

#include<iostream>
#define INITSIZE 20
#define INCREAMENT 5
#define OK 1
#define ERROR 0
#define OVERFLOW -1
using namespace std;
typedef struct Lnode
{
    int key;
    char info;
}LNode;
typedef struct
{
    LNode *r;
    int length;
    int listsize;
}SqList;
int initList(SqList &L)
{
    L.r=(LNode *)malloc(sizeof(LNode) * INITSIZE);
    if(!L.r) exit(OVERFLOW);
    L.length=1;
    L.r[0].key = 0;
    L.listsize=INITSIZE;
    return OK;
}
int Listinsert(SqList &L,int i,LNode *elem)
{
    if(i<1||i>L.length+1)  return ERROR;
    if(L.length>=L.listsize)
    {
        LNode *newbase=(LNode *)realloc(L.r,(L.length+INCREAMENT)*sizeof(LNode));
        if(!newbase) exit(OVERFLOW);
        L.r=newbase;
        L.listsize+=INCREAMENT;
    }
//  L.r[i].key = elem->key;

    LNode *q=&L.r[i];
    for(LNode *p=&(L.r[L.length-1]);p>=q;--p)
    {
        *(p+1)=*p;
    }
    L.r[i].key=elem->key;
    ++L.length;
    return OK;
}
int Partition(SqList &L,int low,int high)
{
    L.r[0].key=L.r[low].key;
    int pivotkey=L.r[low].key;
    while(high>low)
    {
        while(low<high  &&  L.r[high].key>=pivotkey)  --high;

        if(low<high)    L.r[low].key=L.r[high].key;

        while(low<high  &&  L.r[low].key<=pivotkey)    ++low;

        if(low<high) L.r[high].key=L.r[low].key;
    }
    L.r[low].key=pivotkey;
    return high;

}
int Qsort(SqList &L,int low,int high)
{
    if(low<high)
    {
        int pivotkey;
        pivotkey=Partition(L,low,high); cout<<"pivotkey  "<<pivotkey<<"  low "<<low<<"  high "<<high<< endl;
        for(int i=1;i<L.length;++i)
        cout<<L.r[i].key<<"  ";
        cout<<endl;
        Qsort(L,low,pivotkey-1);
        Qsort(L,pivotkey+1,high);
    }
    return OK;
}
int Quicksort(SqList &L)
{
    Qsort(L,1,L.length - 1);
    return OK;
}
int main(void)
{
    SqList L;
    initList(L);
    int i,num;
    cout<<"請輸入排序的個數"<<endl;
    cin>>num;
    for(i=1;i<=num;i++)
    {
        LNode *p=(LNode *)malloc(sizeof(LNode));
        cout<<"輸入關鍵字\n";
        cin>>p->key;
//      cout<<"輸入信息"<<endl;
//      cin>>p->info;
        Listinsert(L,i,p);
    }
    cout<<"排序前:\n";
    for(i=1;i<L.length;++i)
        cout<<L.r[i].key<<"  ";
    //  cout<<"TEST HERE"<<endl;
    cout<<endl;
//  cout<<L.length<<endl;
    Quicksort(L);

    cout<<"排序後:"<<endl;
    for(i=1;i<L.length;++i)
        cout<<L.r[i].key<<"  ";
    return OK;

}