class Solution {
    public int[] twoSum(int[] nums, int target) {

        for (int i = 0; i < nums.length; i++) {
            for (int j = i + 1; j < nums.length; j++) {

                if (nums[i] == target - nums[j]) {
                    return new int[]{i, j};
                }

            }
        }

        throw new IllegalArgumentException("No two sum solution !!!");

    }
}

class Solution {
    public static int[] twoSum(int[] nums, int target) {

        Map<Integer, Integer> map = new HashMap<>();

        for (int i = 0; i < nums.length; i++) {
            int complement = target - nums[i];
            if (map.containsKey(complement)) {
                return new int[]{map.get(complement), i};
            }
            map.put(nums[i], i);
        }
        
        throw new IllegalArgumentException("No two sum solution !!!");

    }
}

class Solution {
        public int removeElement(int[] nums, int val) {
            int count = 0;
            for(int i = 0; i < nums.length; i++){
                if(nums[i] != val){
                    nums[count++] = nums[i];
                }
            }

            return count--;
        }
    }