寒假训练第九场 Brocard Point of a Triangle

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<algorithm>
 4 #include<iostream>
 5 #include<cstdlib>
 6 #include<cstring>
 7 #include<cmath>
 8 #include<vector>
 9 #define clc(a,b) memset(a,b,sizeof(a))
10 using namespace std;
11 const double eps=1e-8;
12 const double pi=acos(-1);
13 const int maxn=1000010;
14 using namespace std;
15 
16 int t;
17 int main()
18 {
19     while(~scanf("%d",&t))
20     {
21         while(t--)
22         {
23             int K;
24             double c,d,a,b,e,f,m1,m2,m3,k,q;
25             double x,y;
26             scanf("%d%lf%lf%lf%lf%lf%lf",&K,&a,&b,&e,&f,&c,&d);
27             double l1,l2,l3;
28             l1=(a-e)*(a-e)+(b-f)*(b-f);
29             l2=(c-e)*(c-e)+(d-f)*(d-f);
30             l3=(c-a)*(c-a)+(d-b)*(d-b);
31             m1=(l1*l3*l3)/(l1*l2+l2*l3+l3*l1);
32             m2=(l3*l2*l2)/(l1*l2+l2*l3+l3*l1);
33             m3=(l2*l1*l1)/(l1*l2+l2*l3+l3*l1);
34             if(a!=c&&b!=d)
35             {
36                 k=(-a+e)/(-a+c);
37                 q=(-b+f)/(-b+d);
38                 x=(e*e-b*b+(1-q)*m1-m3+q*m2+q*(b*b-c*c)+f*f-a*a+q*(a*a-d*d))/(2*q*a-2*q*c-2*a+2*e);
39                 y=(e*e-b*b+m1*(1-k)-m3+k*m2+k*(b*b-c*c)-a*a+f*f+k*(a*a-d*d))/(2*k*b-2*k*d-2*b+2*f);
40                 printf("%d %.5f %.5f\n",K,x,y);
41             }
42             else if(a==c)
43             {
44                 y=(m1-m2+d*d-b*b)/(-2*b+2*d);
45                 x=a+sqrt(m1-(y-b)*(y-b));
46                 printf("%d %.5f %.5f\n",K,x,y);
47             }
48             else
49             {
50                 x=(m1-m2+c*c-a*a)/(-2*a+2*c);
51                 y=b+sqrt(m1-(x-a)*(x-a));
52                 printf("%d %.5f %.5f\n",K,x,y);
53             }
54         }
55     }
56     return 0;
57 }