百度经验网站建设/建站宝盒

https://leetcode-cn.com/problems/kth-largest-element-in-a-stream/

思路：用$treap$之类的数据结构肯定可以搞定，不过这道题目只有插入操作，没有删除操作，且$k$是固定的，那么直接用堆就可以了。维护一个元素个数恰好为$k$的小根堆，那么堆顶元素就是第$k$大元素。

class KthLargest {
public:priority_queue<int,vector<int>,greater<int>> q;int k;KthLargest(int k, vector<int>& nums):k(k),q(move(priority_queue<int,vector<int>,greater<int>>(nums.begin(),nums.end()))) {while(q.size()>k)q.pop();}int add(int val) {q.push(val);if(q.size()>k)q.pop();return q.top();}
};/*** Your KthLargest object will be instantiated and called as such:* KthLargest* obj = new KthLargest(k, nums);* int param_1 = obj->add(val);*/