链接:199. 二叉树的右视图
题单:
思路:
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode() : val(0), left(nullptr), right(nullptr) {}
* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution {
public:
vector<int> res;
void dfs(TreeNode* root, int hi) {
if (!root) return ;
if (hi == res.size()) res.push_back(root->val);
dfs(root->right, hi + 1);
dfs(root->left, hi + 1);
return ;
}
vector<int> rightSideView(TreeNode* root) {
dfs(root, 0);
return res;
}
};