I Think I Need a Houseboat(圆计算）

http://poj.org/problem?id=1005

#include<stdio.h>
int main()
{
    int n, i ;
    float x, y ;
    scanf("%d", &n) ;
    for(i=1; i<=n; i++)
    {
        scanf("%f %f", &x, &y) ;
        float area = 3.14*(x*x + y*y)/2 ;
        int year = (int)(area/50) + 1 ;
        printf("Property %d: This property will begin eroding in year %d.\n", i, year) ;
    }
    printf("END OF OUTPUT.\n") ;
    return 0 ;
}