199. Binary Tree Right Side View

class Solution {
    public List<Integer> rightSideView(TreeNode root) {
        List<Integer> result = new LinkedList<>();
        recursion(root, result, 1);
        return result;
    }
    private void recursion(TreeNode node, List<Integer> list, int level){
        if(node == null) return;
        if(level>list.size()){
            list.add(node.val);
        }
        
        recursion(node.right, list, level+1);
        recursion(node.left, list, level+1);
    }
}