leetcode703+第k大的数字，最小堆使用

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

class KthLargest {
public:
    int size;
    priority_queue<int, vector<int>, greater<int>> Q;
    KthLargest(int k, vector<int> nums) {
        size = k;
        for(auto num:nums){
            Q.push(num);
            if(Q.size()>size){
                Q.pop();
            }
        }
    }
    
    int add(int val) {
        Q.push(val);
        if(Q.size()>size) 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);
 */