Largest Positive Integer That Exists With Its Negative

Given an integer array nums that does not contain any zeros, find the largest positive integer k such that -k also exists in the array.

Return the positive integer k. If there is no such integer, return -1.

LeetCode Problem - 2441

import java.util.HashSet;

class Solution {
    // Method to find the maximum value of k such that both k and -k exist in the array
    public int findMaxK(int[] nums) {
        // Initialize the result variable to store the maximum value of k
        int result = -1;
        // Create a HashSet to store unique elements from the array
        HashSet<Integer> hs = new HashSet<>();
        // Add all elements of the array to the HashSet
        for(int e : nums) {
            hs.add(e);
        }

        // Iterate through the array to find the maximum value of k
        for(int k : nums) {
            // Check if k is positive and its negation (-k) exists in the HashSet
            if(k > 0 && hs.contains(-k)) {
                // Update the result with the maximum of the current k and the previous result
                result = Math.max(result, k);
            }
        }

        // Return the maximum value of k found
        return result;
    }
}