/in/foo.cc: In function 'int main()':
/in/foo.cc:60:29: warning: 'yc' may be used uninitialized in this function [-Wmaybe-uninitialized]
  printf("%.3lf %.3lf",xc,yc);
                             ^
/in/foo.cc:60:29: warning: 'xc' may be used uninitialized in this function [-Wmaybe-uninitialized]