快速排序的随机化算法

//快速排序的随机化算法
#include <stdio.h>
#include <stdlib.h>
#define N 10

//Exchange the value
void swap(int *p,int *q)
{
	int temp;
	temp=*p;
	*p=*q;
	*q=temp;
}
//generate a random number between p and q
int random(int p,int q)
{
	int result=p+rand()%(q-p+1);
	return result;
}
//patition
int partition(int A[],int p,int q)
{
	int j=p,i=j-1,temp;;
	int r=A[q];
	for(int k=p;k<q;k++)
	{
		if(A[k]<=r)
		{
			i=i+1;
			temp=A[i];
			A[i]=A[k];
			A[k]=temp;
		}
	}
	temp=A[i+1];
	A[i+1]=A[q];
	A[q]=temp;
	return i+1;
}
//random_partition
int random_partition(int A[],int p,int q)
{
	int i=random(p,q);
	swap(&A[i],&A[q]);
	return partition(A,p,q);
}

//randomized_quicksort
void randomized_quicksort(int A[],int p,int q)
{
	int r;
	if(p<q)
	{
		r=random_partition(A,p,q);
		randomized_quicksort(A,p,r-1);
		randomized_quicksort(A,r+1,q);
	}
}

int main()
{
	int A[N],i;
	for(i=0;i<N;++i)
		scanf("%d",&A[i]);
	randomized_quicksort(A,0,9);
	for(i=0;i<N;++i)
		printf("%d ",A[i]);
	printf("\n");
}