剑指offer：最小k个数

class Solution {
public:
    vector<int> GetLeastNumbers_Solution(vector<int> input, int k) {
        if (k == 0 || k > input.size()) return {};
        priority_queue<int> p;
        vector<int> ans;
        for(int i = 0; i < k; i++){
            p.push(input[i]);
        }
        for(int i = k; i < input.size(); i++){
            if(input[i] < p.top()){
                p.pop();
                p.push(input[i]);
            }
        }
        for(int i = 0; i < k; i++){
            ans.push_back(p.top());
            p.pop();
        }
        return ans;
        
    }
};

class Solution {
public:
    vector<int> GetLeastNumbers_Solution(vector<int> input, int k) {
        if(k > input.size() || input.empty()) return {};
        vector<int> ans;
        sort(input.begin(), input.end());
        for(int i = 0; i < k; i++){
            ans.push_back(input[i]);
        }
        
        return ans;
    }
};

class Solution {
public:
    vector<int> GetLeastNumbers_Solution(vector<int> input, int k) {
        if(k > input.size() || input.empty()) return {};
        vector<int> ans;
        for(int i = 0; i < k; i++){
            for(int j = 0; j < input.size()-i - 1; j++){
                if(input[j] < input[j+1]){
                    int tmp = input[j];
                    input[j] = input[j+1];
                    input[j+1] = tmp;
                }
            }
            ans.push_back(input[input.size()-i-1]);
        }
        
        return ans;
    }
};