快速排序

#include<iostream>
#include<iterator>
#include<vector>
#include<algorithm>
#include<time.h>
using namespace std;

/*
*快速排序问题
*/
void Fast_sort(vector<int>& a,int beg,int end)
{
	if(beg+1>=end) return;
	int key = beg;
	for (int i = beg , j = end; i < j; )
	{
		if(key == i)
		{
			do
			{
				j--;
			} while (a[j]>a[key]);
			key = j;
		}else
		{
			do
			{
				i++;
			} while (a[i]<a[key]);
			key = i;
		}
		swap(a[i],a[j]);
	}
	Fast_sort(a,beg,key);
	Fast_sort(a,key+1,end);
}

int main()
{
	long start, end;
	vector<int> vec;
	copy(istream_iterator<int>(cin),istream_iterator<int>(),back_inserter(vec));
	start = clock();
	Fast_sort(vec,0,vec.size());
	end = clock();
	copy(vec.begin(),vec.end(),ostream_iterator<int>(cout," "));
	cout<<endl;
	cout <<"程序运行时间（单位：毫秒）： "<< end-start <<endl;
}

快速排序

原文：http://blog.csdn.net/yyc1023/article/details/41311429