[Leetcode] Binary Tree Inorder Traversal(Easy)
LeetCode 94 - Binary Tree Inorder Traversal
Given the root of a binary tree, return the inorder traversal of its nodes’ values.
example
Input: root = [1,null,2,3]
Output: [1,3,2]
Input: root = []
Output: []
Input: root = [1]
Output: [1]
How can we solve this problem?
這題很簡單,只要使用中序遍歷即可。
Solution:
/**
* 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> inorderTraversal(TreeNode* root) {
vector<int> res;
inorder(root,res);
return res;
}
void inorder(TreeNode* root,vector<int>& res){
if(!root) return;
inorder(root->left,res);
res.emplace_back(root->val);
inorder(root->right,res);
}
};