#include <iostream>
#include <cstdio>
#include <algorithm>
#include <ctime>
#include <cstdlib>
using namespace std;
const int maxn = 10000;
int a[maxn],b[maxn],c[maxn];
void quicksort(int *a,int left,int right)
{
	int i,j;
	if(left<right)
	{
		i=left;j=right;
		a[0]=a[i];
		while(i!=j)
		{//向左找小於a[0]的數
			while(a[j]>a[0] && i<j)	j--;
			if(i<j)	
			{
				a[i]=a[j];
				i++;
			}
			//向右找大於當前儲存的數
			while(a[i]<a[0] && i<j)	i++;
			if(i<j)
			{
				a[j]=a[i];j--;
			}
		}
		a[i]=a[0];
		quicksort(a,left,i-1);
		quicksort(a,i+1,right);
	}
}

void select_sort(int *a)
{
	int i,j,t,tt;
	for(i=1;i<=maxn-2;i++)
	{
		t=i;
		for(j=i+1;j<=maxn-1;j++)
		{
			if(a[t]>a[j])
			{
				t=j;
			}
		}
		if(t!=i)
		{
			tt=a[i];a[i]=a[t];a[t]=tt;
		}
	}
}

int main ()
{
	int i;
	a[0]=0;b[0]=0;c[0]=0; 
	clock_t start, finish; 
	double T;
	start = clock();
	//陣列a賦值
	for(i=1;i<maxn;i++)
	{
		a[i]=(rand()%(10000+1));
	}
	quicksort(a,1,maxn-1);
	finish = clock();
	T = (double)(finish - start) / CLOCKS_PER_SEC;
	printf("quicksort:Running Time:%lf\n",T);
	//陣列b賦值
	for(i=1;i<maxn;i++)
	{
		b[i]=(rand()%(10000+1));
	}
	start = clock();
	select_sort(b);
	finish = clock();
	T = (double)(finish - start) / CLOCKS_PER_SEC;
	printf("select_sort:Running Time:%lf\n",T);
	//陣列c賦值
	for(i=1;i<maxn;i++)
	{
		c[i]=(rand()%(10000+1));
	}
	start = clock();
	sort(c+1,c+maxn);
	finish = clock();
	T = (double)(finish - start) / CLOCKS_PER_SEC;
	printf("sort():Running Time:%lf\n",T);	 
	return 0;
}
 

選擇排序演算法效率高很多