LeetCode-in-Java

1471. The k Strongest Values in an Array

Medium

Given an array of integers arr and an integer k.

A value arr[i] is said to be stronger than a value arr[j] if |arr[i] - m| > |arr[j] - m| where m is the median of the array.
If |arr[i] - m| == |arr[j] - m|, then arr[i] is said to be stronger than arr[j] if arr[i] > arr[j].

Return a list of the strongest k values in the array. return the answer in any arbitrary order.

Median is the middle value in an ordered integer list. More formally, if the length of the list is n, the median is the element in position ((n - 1) / 2) in the sorted list (0-indexed).

Example 1:

Input: arr = [1,2,3,4,5], k = 2

Output: [5,1]

Explanation: Median is 3, the elements of the array sorted by the strongest are [5,1,4,2,3]. The strongest 2 elements are [5, 1]. [1, 5] is also accepted answer. Please note that although |5 - 3| == |1 - 3| but 5 is stronger than 1 because 5 > 1.

Example 2:

Input: arr = [1,1,3,5,5], k = 2

Output: [5,5]

Explanation: Median is 3, the elements of the array sorted by the strongest are [5,5,1,1,3]. The strongest 2 elements are [5, 5].

Example 3:

Input: arr = [6,7,11,7,6,8], k = 5

Output: [11,8,6,6,7]

Explanation: Median is 7, the elements of the array sorted by the strongest are [11,8,6,6,7,7]. Any permutation of [11,8,6,6,7] is accepted.

Constraints:

Solution

import java.util.Arrays;

public class Solution {
    public int[] getStrongest(int[] arr, int k) {
        Arrays.sort(arr);
        int[] array = new int[k];
        int median = arr[(arr.length - 1) / 2];
        int start = 0;
        int end = arr.length - 1;
        for (int i = 0; i < k; i++) {
            if (Math.abs(arr[end] - median) >= Math.abs(arr[start] - median)) {
                array[i] = arr[end];
                end -= 1;
            } else {
                array[i] = arr[start];
                start += 1;
            }
        }
        return array;
    }
}