C++ priority_queue overload comparison function

C++_priority_queue_overload_cmp.cpp

struct com{
  bool operator()( T &t1, T &t2) {
      if(t1.x != t2.x) {
             return t1.x < t2.x -->按x降序
      }
      return t1.y > t2.y   -->x相等时按y升序
  }
};

priority_queue<T, vector<T>, com>  que;