重载运算符

struct student {
  string name;
  int score;

  bool operator<(const student& a) const {
    return score < a.score || (score == a.score && name > a.name);
    // 上面省略了 this 指针，完整表达式如下：
    // this->score<a.score||(this->score==a.score&&this->name>a.name);
  }
};

priority_queue<student> pq;

上面的代码将小于号重载为了成员函数，当然重载为非成员函数也是可以的。

struct student {
  string name;
  int score;
};

bool operator<(const student& a, const student& b) {
  return a.score < b.score || (a.score == b.score && a.name > b.name);
}

priority_queue<student> pq;

构造函数等价于c++里面 { } 

如果要开数组，需要加上 = 0作为初始化

struct Queue {
	int num, id;
	Queue(int _num = 0, int _id = 0) :
		num(_num), id(_id) {}
	bool operator < (const Queue &t) const {
		if(num == t.num) return id < t.id;
		return num < t.num;
	}
}q[N];