public static int[] twoSum(int[] nums, int target) { Map<Integer,Integer> map = new HashMap(); int[] a = new int[2]; for (int i = 0; i < nums.length; i++) { if (map.containsKey(target-nums[i])){ a[0] = map.get(target-nums[i]); a[1] = i; }else { map.put(nums[i],i); } } return a; }