题解 | #输入n个整数，输出其中最小的k个#

import java.util.*;

public class Main {

public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
    //最大的k个->小根堆，最小的k个->大根堆
    PriorityQueue<Integer> pq = new PriorityQueue<>((x, y) -> (y - x));
    while (in.hasNextInt()) {
        int n = in.nextInt(), k = in.nextInt();
        int[] nums = new int[n];
        //用数组承接输入整数
        for (int i = 0; i < n; i++) {
            nums[i] = in.nextInt();
        }
        //利用大根堆特性将最小的k个存入
        for(int num : nums){
            if(pq.size() == k && pq.peek() > num) pq.poll();
            if(pq.size() < k) pq.offer(num);
        }
        //用数组将大根堆中的元素倒序存入
        int[] res = new int[pq.size()];
        for(int i = res.length - 1; i >= 0; i--) res[i] = pq.poll();
        //从小到大输出
        for(int i = 0; i < k; i++){
            if(i == k - 1) System.out.print(res[i]);
            else System.out.print(res[i] + " ");
        }
    }
} 

}