LC94 Binary Tree Inorder Travers

本题链接：Binary Tree Inorder Traversal

本题标签：Tree, Hash Table, Stack

本题难度：

方案1：

class Solution {  
public:
    vector<int> inorderTraversal(TreeNode* root) {
        vector<int> res;
        
        stack<TreeNode*> stk;
        TreeNode *cur = root;
        while(cur != NULL || stk.size())
        {
            while(cur != NULL)
            {
                stk.push(cur);
                cur = cur->left;
            }
            cur = stk.top();
            res.push_back(cur->val);
            stk.pop();
            cur = cur->right;
        }
        
        return res;
    }
};

时间复杂度：

空间复杂度：