【LeetCode热题100】【二叉树】二叉树的右视图

class Solution {
public:
    vector<int> ans;

    void dfs(TreeNode *root, int depth) {
        if (root == nullptr)
            return;
        if (depth == ans.size())
            ans.push_back(root->val);
        dfs(root->right, depth + 1);
        dfs(root->left, depth + 1);
    }

    vector<int> rightSideView(TreeNode *root) {
        dfs(root, 0);
        return ans;
    }
};