import java.util.Map; import java.util.HashMap; public class Solution { public static int[] twoSum(int[] numbers, int target) { Map encountered = new HashMap<>(); for (int i = 0; i < numbers.length; i++) { Integer other = encountered.get(target - numbers[i]); if (other != null) { return new int[] {other, i}; } encountered.put(numbers[i], i); } return null; // Do your magic! } }