Leetcode 94. Binary Tree Inorder Traversal (Medium) (cpp)

Leetcode 94. Binary Tree Inorder Traversal (Medium) (cpp)

Tag: Tree, Hash Table, Stack

Difficulty: Medium

/*94. Binary Tree Inorder Traversal (Medium)Given a binary tree, return the inorder traversal of its nodes' values.For example:Given binary tree [1,null,2,3],   1    \     2    /   3return [1,3,2].Note: Recursive solution is trivial, could you do it iteratively?*//** * Definition for a binary tree node. * struct TreeNode { *     int val; *     TreeNode *left; *     TreeNode *right; *     TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class Solution {public:    vector<int> inorderTraversal(TreeNode* root) { vector<int> res; traversal(root, res); return res; } void traversal(TreeNode* root, vector<int>& res) { if (root) { traversal(root -> left, res); res.push_back(root -> val); traversal(root -> right, res); } }};