Leetcode: Binary Tree inorder Traversal

Title: Binary Tree inorder Traversal

The central traversal of a binary tree is the same as that of the forward and middle order. For the code, see:

 1 struct TreeNode { 2     int            val; 3     TreeNode*    left; 4     TreeNode*    right; 5     TreeNode(int x): val(x), left(NULL),right(NULL) {} 6 }; 7  8 vector<int> preorderTraversal(TreeNode *root) //非递归的中序遍历(用栈实现) 9 {10     if (NULL == root) {11         return vector<int>();12     }13 14     stack<TreeNode *> tree_stack;15     vector<int> tree_vector;16 17     TreeNode *pTemp = root;18     while (pTemp || !tree_stack.empty()) {19         while (pTemp) {20             tree_stack.push(pTemp);21             pTemp = pTemp->left;22         }23         if (!tree_stack.empty()) {24             pTemp = tree_stack.top();25             tree_vector.push_back(pTemp->val);26             tree_stack.pop();27             pTemp = pTemp->right;28         }29     }30     return tree_vector;31 }

 

Leetcode: Binary Tree inorder Traversal