import java.lang.*;
import java.util.*;

class TwoSum {
	public static int[] twoSum(int[] nums, int target) {
		HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();
		for (int i = 0; i < nums.length; i++) {
			if (map.containsKey(target - nums[i]))
				return new int[] {map.get(target - nums[i]), i};
			map.put(nums[i], i);
		}
		return new int[] {-1, -1};
	}

	public static void main(String[] args) {
		int[] nums = {2, 7, 11, 15};
		int target = 9;
		System.out.println(Arrays.toString(twoSum(nums, target)));
	}
}