> #include<stdio.h>
> 
> int main()
> {
> 	int n,i,j;
> 	long d;
> 	unsigned char *c = &d;
> 	scanf("%d",&n);
> 	for(i=0;i<n;i++)
> 	{
> 		while(getchar()!='\n') ;
> 		d=0;
> 		for(j=31;j>=0;j--)
> 			if (getchar()=='1') d|=1<<j;
> 		printf("%d.%d.%d.%d\r\n",c[3],c[2],c[1],c[0]);
> 	}
> 	return 0;
> }


方法挺巧妙