LeetCode Two Sum

 1 public class Solution {
 2     public int[] twoSum(int[] nums, int target) {
 3         if(nums == null || nums.length < 2){
 4             return new int[]{-1,-1};
 5         }
 6         
 7         int [] res = new int[]{-1,-1};
 8         Map<Integer, Integer> hm = new HashMap<Integer, Integer>();
 9         
10         for(int i = 0; i<nums.length; i++){
11             if(!hm.containsKey(target-nums[i])){
12                 hm.put(nums[i],i);
13             }else{
14                 res[0] = hm.get(target - nums[i])+1;
15                 res[1] = i+1;
16                 break;
17             }
18         }
19         return res;
20     }
21 }