TwoSumII.java

import java.util.Arrays;

public class TwoSumII {

    public static int[] twoSum(int[] numbers, int target) {
        int left = 0;
        int right = numbers.length - 1;

        while (left < right) {
            int sum = numbers[left] + numbers[right];

            if (sum == target) {
                return new int[]{left + 1, right + 1};
            } 
            else if (sum < target) {
                left++;
            } 
            else {
                right--;
            }
        }

        return new int[]{-1, -1};
    }

    public static void main(String[] args) {

        int[] numbers = {2,7,11,15};
        int target = 9;

        int[] result = twoSum(numbers, target);

        System.out.println(Arrays.toString(result));
    }
}