class Solution {    public int[] twoSum(int[] nums, int target) {         if(nums == null || nums.length < 2){            return new int[]{-1, -1};        }        int[] res = new int[]{-1,-1};        HashMap
     
       map = new HashMap<>();        for(int i = 0; i < nums.length; i++){            if(map.containsKey(target - nums[i])){                res[0] = map.get(target - nums[i]);                res[1] = i;            }            map.put(nums[i],i);        }        return res;    }}