Two Sum

class Solution {
    public int[] twoSum(int[] nums, int target) {
        HashMap<Integer, Integer> map = new HashMap<>();

        for(int i = 0; i< nums.length; i++){
            int a = nums[i];
            int more = target - a;

            if(map.containsKey(more)){
                return new int[]{map.get(more), i};
            }
            map.put(nums[i], i);
        }
        throw new IllegalArgumentException("No two sum found");
    }
}