> #include <stdio.h>
> long tri(int n)
> {
> 	if(n==1)return 3;
> 	if(n==2)return 11;
> 	long sum,i,temp;
> 	sum=1;
> 	temp=3;
> 	for(i=1;i<n;i++){
> 		sum=sum+temp;
> 		temp=3*temp+2*(sum-temp);
> 	}
> 	return temp;
> }
> void main()
> {
> 	int input;
> 	scanf("%d",&input);
> 	while(input!=-1){
> 		if(input%2==1||input==0)printf("0\n");
> 		else printf("%ld\n",tri(input/2));
> 		scanf("%d",&input);
> 	}
> }

• 谢谢，我过了^_^ (0) gardner 2005-10-16 00:08:40