poj 2959（水题）

#include<iostream>
#include<cmath>
#include<cstdio>
using namespace std;
#define PI 3.1415927 
int main(){
    int n;
    double D,d,s,tmp;
    scanf("%d",&n);
    for(int kase=1;kase<=n;kase++){
        scanf("%lf%lf%lf",&D,&d,&s);
        int ans = 3;
        for(int i=3;;i++){
            tmp = (D-d)*cos((i-2)*PI/2/i)-d;
            if(tmp<s){
                ans = i-1;
                break;
            }
        }
        printf("%d\n",ans);
    }
    return 0;
}