三角形外心

题目：https://ac.nowcoder.com/acm/contest/4692/A

#include<iostream>
#include<cstdio>
using namespace std;
int main(){
 double x1,y1,x2,y2,x3,y3,a1,a2,b1,b2,c1,c2;
 cin>>x1>>y1>>x2>>y2>>x3>>y3;
 a1=2*(x2-x1);b1=2*(y2-y1); c1=x2*x2+y2*y2-x1*x1-y1*y1;
 a2=2*(x3-x2);b2=2*(y3-y2); c2=x3*x3+y3*y3-x2*x2-y2*y2;
 printf("%.3f ",(c1*b2-c2*b1)/(a1*b2-a2*b1));
 printf("%.3f",(a1*c2-a2*c1)/(a1*b2-a2*b1));
 return 0;
} 

来源：CSDN

作者：小白白同学&

链接：https://blog.csdn.net/weixin_45825917/article/details/104542665