1class Solution {2    public List<Integer> rightSideView(TreeNode root) {3        List<Integer> result = new ArrayList<>();4        visit(root, 0, result);5        return result;6    }7    private void visit(TreeNode node, int depth, List<Integer> result) {8        if (node == null) return;9        if (depth == result.size()) result.add(node.val);10        visit(node.right, depth + 1, result);11        visit(node.left, depth + 1, result);12    }13}