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 scan = new Scanner(System.in);
        String nk = scan.nextLine();
        int n = Integer.valueOf(nk.split(" ")[0].trim());
        int k = Integer.valueOf(nk.split(" ")[1].trim());
        String line = scan.nextLine();
        String[] numsStr = line.split(" ");
        int[] nums = new int[numsStr.length];
        for (int i = 0; i < numsStr.length; i++) {
            nums[i] = Integer.valueOf(numsStr[i]);
        }
        heapSort(nums);
        for (int i = 0; i < k; i++) {
            if (i == k - 1) {
                System.out.print(nums[i]);
                return;
            }
            System.out.print(nums[i] + " ");
        }
    }
    public static void heapSort(int[] nums) {
        if (null == nums || nums.length < 2) {
            return;
        }
        for (int i = 0; i < nums.length; i++) {
            heapInsert(nums, i);
        }
        int heapSize = nums.length;
        swap(nums, 0, --heapSize);
        while (heapSize > 0) {
            heapify(nums, 0, heapSize);
            swap(nums, 0, --heapSize);
        }
    }
    public static void heapInsert(int[] nums, int index) {
        while (nums[index] > nums[(index - 1) / 2]) {
            swap(nums, index, (index - 1) / 2);
            index = (index - 1) / 2;
        }
    }
    public static void heapify(int[] nums, int index, int heapSize) {
        int left = index * 2 + 1;
        while (left < heapSize) {
            int largest = left + 1 < heapSize && nums[left + 1] > nums[left] ? left + 1 : left;
            largest = nums[largest] > nums[index] ? largest : index;
            if (largest == index) {
                break;
            }
            swap(nums, index, largest);
            index = largest;
            left = index * 2 + 1;
        }
    }
    public static void swap(int[] nums, int p1, int p2) {
        int tmp = nums[p1];
        nums[p1] = nums[p2];
        nums[p2] = tmp;
    }
}