ZOJ-1049 几何算数题

1049:选一坐标点建房。河水淹没区域是半圆形，每年扩大50平方英里。问几年能淹到房子。





Sample Input:

2
1.0 1.0
25.0 0.0



Sample Output:

Property 1: This property will begin eroding in year 1.
Property 2: This property will begin eroding in year 20.
END OF OUTPUT.


简单题。就是比较圆半径和点到原点距离。

#include<stdio.h>
#include<iostream>
using namespace std;

#define PI 3.1415927

int main()
{	
	int N;
	double x;
	double y;
	int area;
	int k;
	cin>>N;
	for(int i=1;i<=N;i++)
	{
		cin>>x;
		cin>>y;
		area=0;
		//半圆面积1/2*PI*r*r
		for(k=0;;k++)
		{
			if(2*area/PI>x*x+y*y)
				break;
			else
				area+=50;
		}
		printf("Property %d: This property will begin eroding in year %d.\n",i,k);
	}
	printf("END OF OUTPUT.\n"); 
	
}