quicksort.cpp

我们编写的是一个实现快速排序算法的c++程序

#include<stdio.h>
void swap(int &a,int &b)
{
	int temp;
	temp=a;
	a=b;
	b=temp;
}

int pivotlist(int list[],int first,int last)
{
	int index,pivotvalue=list[first],pivotpoint=first;
	for(index=first+1;index<=last;index++)
	{
		if(list[index]<pivotvalue)
		{
			pivotpoint=pivotpoint+1;
			swap(list[pivotpoint],list[index]);
		}
	}
	swap(list[first],list[pivotpoint]);
	return pivotpoint;
}

void quicksort(int list[],int first,int last)
{
	int pivot;
	if(first<last)
	{
		pivot=pivotlist(list,first,last);
		quicksort(list,first,pivot-1);
		quicksort(list,pivot+1,last);
	}
}

int main()
{
	int a[6]={2,4,9,6,3,5},i;
	for(i=0;i<6;i++)
		printf("%d ",a[i]);
	printf("\nafter quicksorting,the list is:\n");
	quicksort(a,0,5);
	for(i=0;i<6;i++)
		printf("%d ",a[i]);
	printf("\n");
	return 0;
}