> #include<stdio.h>
> #define PI 3.1415926
> void main()
> {
> 	unsigned int N,i,j,a[10];
> 	double x[10],y[10],s=0;
> 	scanf("%d",&N);
> 	for(i=0;i<N;i++)
> 		scanf("%lf%lf",&x[i],&y[i]);
> 	for(j=0;j<N;j++)
> 		{
> 			for(a[j]=0;(x[j]*x[j]+y[j]*y[j])>s;a[j]++)
> 				s=(a[j]+1)*100/PI;	
> 		}
> 	for(j=1;j<=N;j++)
> 		{
> 			printf("Property %d: This property will begin eroding in year %d.\n",j,a[j-1]);
> 		}
> 	printf("END OF OUTPUT.\n");
> }


s必须每次都赋成0