UVa 11524 - InCircle

 1 #include <cstdio>
 2 #include <cmath>
 3 
 4 double Cal( double a, double b, double c )
 5 {
 6     return a + b - c;
 7 }
 8 
 9 int main()
10 {
11     int T;
12     scanf( "%d", &T );
13     while ( T-- )
14     {
15         double m[3], n[3], r;
16         scanf( "%lf", &r );
17         for ( int i = 0; i < 3; ++i )
18             scanf( "%lf%lf", &m[i], &n[i] );
19 
20         double k[3];
21         k[0] = 1.0;
22         k[1] = n[1] * ( m[2] + n[2] ) / ( m[2] * ( m[1] + n[1] ) );
23         k[2] = m[1] * ( m[0] + n[0] ) / ( n[0] * ( m[1] + n[1] ) );
24 
25         double a = sqrt( 4.0*(k[0]+k[1]+k[2])*r*r / ( Cal(k[1], k[2], k[0])*Cal(k[0], k[2], k[1])*Cal(k[0], k[1], k[2]) ) );
26         double b = k[1] * a;
27         double c = k[2] * a;
28         double ans = ( a + b + c ) * r / 2.0;
29         printf( "%.4f\n", ans );
30     }
31     return 0;
32 }