/**
knakul853
 */
class Solution {
public:
    vector<int>ans;
    vector<int> rightSideView(TreeNode* root) {

        dfs(root, 0);

        return ans;
    }

    void dfs( TreeNode* root, int lvl)
    {
        if(!root) return;

        if((int)ans.size() == lvl) ans.push_back(root->val);

        dfs(root->left, lvl+1);
                dfs(root->right, lvl+1);

    }
};