UVa 11524 - InCircle

推公式

 #include <cstdio>
 #include <cmath>

 double Cal( double a, double b, double c )
 {
     return a + b - c;
 }

 int main()
 {
     int T;
     scanf( "%d", &T );
     while ( T-- )
     {
         double m[], n[], r;
         scanf( "%lf", &r );
         for ( int i = ; i < ; ++i )
             scanf( "%lf%lf", &m[i], &n[i] );

         double k[];
         k[] = 1.0;
         k[] = n[] * ( m[] + n[] ) / ( m[] * ( m[] + n[] ) );
         k[] = m[] * ( m[] + n[] ) / ( n[] * ( m[] + n[] ) );

         double a = sqrt( 4.0*(k[]+k[]+k[])*r*r / ( Cal(k[], k[], k[])*Cal(k[], k[], k[])*Cal(k[], k[], k[]) ) );
         double b = k[] * a;
         double c = k[] * a;
         double ans = ( a + b + c ) * r / 2.0;
         printf( "%.4f\n", ans );
     }
     return ;
 }