Total Accepted: 98729 Total Submissions: 261539 Difficulty: Medium
Given a binary tree, return the inorder traversal of its nodes' values.
For example:
Given binary tree {1,#,2,3}
,
1 2 / 3
return [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; stack<TreeNode*> stk; while(root || !stk.empty()){ while(root){ stk.push(root); root=root->left; } if(!stk.empty()){ root = stk.top(); stk.pop(); res.push_back(root->val); root = root->right; } } return res; } };