/in/foo.cc: In member function 'par treap::split(int, int)':
/in/foo.cc:58:2: warning: no return statement in function returning non-void [-Wreturn-type]
  }
  ^
/in/foo.cc: In member function 'int treap::merge(int, int)':
/in/foo.cc:69:2: warning: no return statement in function returning non-void [-Wreturn-type]
  }
  ^
/in/foo.cc: In function 'int build(int)':
/in/foo.cc:100:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^