快速排序

#include <iostream>
#include <stdlib.h>
#include <time.h>
using namespace std;

int partition(int a[],int l,int r){
	int i=l,j=r+1;
	int x=a[l];
	while(true){
		while(a[++i]<x&&i<r);
		while(a[--j]>x);
		if(i>=j)break;
		swap(a[i],a[j]);
		}
	a[l]=a[j];
	a[j]=x;
	return j;
	}
void quickSort(int a[],int l,int r){
	if(l<r){
		int p=partition(a,l,r);
		quickSort(a,l,p-1);
		quickSort(a,p+1,r);
		}
	}

int randPartition(int a[],int l,int r){
	int i=rand()%(r-l+1)+l;
	swap(a[l],a[i]);
	return partition(a,l,r);

	}
void randQuickSort(int a[],int l,int r){
	if(l<r){
		int i=randPartition(a,l,r);
		randQuickSort(a,l,i-1);
		randQuickSort(a,i+1,r);
		}
	}

void main(){
	srand(time(NULL));
	const int n=10;
	int a[n];
	for(int i=0;i<n;i++){
		a[i]=rand()%100+1;
		cout<<a[i]<<" ";
		}
	cout<<endl;
	randQuickSort(a,0,n-1);
	for(int i=0;i<n;i++)
		cout<<a[i]<<" ";
	cout<<endl;

	
	cout<<endl;
	system("pause");
	}


原文地址:https://www.cnblogs.com/xinyuyuanm/p/2979649.html