> #include<stdio.h>
> #define PI 3.141592635
> int main()
> {
> 	int i,n,year;
> 	float x,y,s;
> 	scanf("%d",&n);
> 	for(i=0;i<n;i++)
> 	{
> 		scanf("%f%f",&x,&y);
> 		s=0.5*PI*(x*x+y*y);
> 		if(s%50==0)
> 			year=s/50;
> 		else
> 			year=s/50+1;
> 		printf("Property %d:This property will begin eroding in year %d.\n",i+1,year);
> 	}
> 	printf("END OF OUTPUT.\N");
> 	return 0;
> }

1.s是float类型,50是整型，%是整型运算吧，我系统上gcc会报错
2.最后那个是printf("END OF OUTPUT.\n");你把回车符的n打成大写了……