priority_queue

#inculde<queue>  // 优先队列的头文件

priority_queue<int, vector<int>, less<int>>maxHeap;  // 大顶堆
priority_queue<int, vector<int>, greater<int>>minHeap; // 小顶堆

maxHeap.push(num);
maxHeap.top();
maxHeap.pop();
maxHeap.empty();
maxHeap.size();