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
         
           inorderTraversal(TreeNode* root) {        vector
          
            res;        stack
           
             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;    }};
           
          
         

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