Sword To Offer 029 - 最小的K个数

class Solution {
public:
    vector<int> GetLeastNumbers_Solution(vector<int> input, int k) {
        if(input.size() < k) {
            return vector<int>(0);
        }
        auto compare = [](int a, int b) {
            return b > a;
        };
        priority_queue<int, vector<int>, decltype(compare)> priorityQueue(compare);
        for(auto number : input) {
            priorityQueue.push(number);
            while(priorityQueue.size() > k) {
                priorityQueue.pop();
            }
        }
        vector<int> res;
        while(!priorityQueue.empty()) {
            res.push_back(priorityQueue.top());
            priorityQueue.pop();
        }
        return res;
    }
};