HDU--warmup2(1005)

来源：互联网发布：逻辑回归模型知乎编辑：程序博客网时间：2024/06/06 05:06

三角形外接圆的圆心在三角形中心上，就轻松解决了。

#pragma warning(disable:4786)#include<iostream>#include<algorithm>#include<cmath>#include<stdio.h>#include<time.h>#include<stdlib.h>#include<queue>#include<set>#include<vector>#include<string>#include<ctime>#include<string.h>using namespace std;#define pi acos(-1.0)//#define LL __int64typedef long long LL;#define INF 0x7fffffffffffffffdin)#define bug puts("hear!")#define inf 0x7fffffff#define FRE freopen("in.txt","r",st#define E exp(1.0)#define mod 1000000007const double eps=1e-14;int main(){    int T,tt=0;    double x1,y1,x2,y2,x3,y3,xx,yy,x,y;    cin>>T;    while(T--)    {        cin>>x1>>y1>>x2>>y2>>x3>>y3>>xx>>yy;        x=(x1+x2+x3)/3;        y=(y1+y2+y3)/3;        double r,rr;        r=sqrt((x1-x)*(x1-x)+(y1-y)*(y1-y));        rr=sqrt((x-xx)*(x-xx)+(y-yy)*(y-yy));        if(rr-r<eps)cout<<"Case #"<<++tt<<": Danger"<<endl;        else cout<<"Case #"<<++tt<<": Safe"<<endl;    }    return 0;}