/**

 * Definition for a binary tree node.

 * public class TreeNode {

 *     int val;

 *     TreeNode left;

 *     TreeNode right;

 *     TreeNode(int x) { val = x; }

 * }

 */

class Solution {

    List<List<Integer>> temp = new ArrayList<>();

    public List<Integer> rightSideView(TreeNode root) {

        if(root==null) return new ArrayList<Integer>();

        dfs(root,0);

        List<Integer> ans = new ArrayList<>();

        for(int i=0;i<temp.size();i++){

            List<Integer> list = temp.get(i);

            ans.add(list.get(list.size()-1));

        }

        return ans;

    }

    public void dfs(TreeNode node,int depth){

        if(node==null){

            return;

        }

        if(temp.size()==depth){

            temp.add(new ArrayList<>());

        }

        temp.get(depth).add(node.val);

        dfs(node.left,depth+1);

        dfs(node.right,depth+1);

    }

}