bit2.c

#include <stdio.h>
#include <stdlib.h>

#define BITNUMBER 32
#define N 10000000
#define random(x) rand()%x

int a[N/BITNUMBER+1];

void set(int i)
{
	a[i/BITNUMBER]|=1<<(i%BITNUMBER);
}

void clean(int i)
{
	a[i/BITNUMBER]&=~1<<(i%BITNUMBER);
}

int test(int i)
{
	return (a[i/BITNUMBER]>>(i%BITNUMBER))&1;
}
int main()
{
	int i,temp;
	for(i=0;i<10000000;i++)
		clean(i);
	i=0;
	while(i<1000000)   //1000000个不重复的随机数
	{
		temp=random(10000000);
		if(!test(temp)){
			i++;
			set(temp);
		}
	}
	for(i=0;i<10000000;i++)
		if(test(i))
			printf("%d\n",i);
	return 0;
}