zoj-1047-I Think I Need a Houseboat

#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<math.h>
#define PI 3.1415926
using namespace std;
int main()
{
    int n,t;
    double x,y,k;
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
    {
        scanf("%lf%lf",&x,&y);
        k=(PI*(x*x+y*y))/100.+0.499;
        printf("Property %d: This property will begin eroding in year %.0lf.
",i,k);
    }
    printf("END OF OUTPUT.
");
    return 0;
}

思路很简单 计算给定点到原点的距离，，算面积   主要是精度的控制