[LintCode]67.二叉树的中序遍历

给出一棵二叉树,返回其中序遍历

样例

给出二叉树 {1,#,2,3},

   1    \     2    /   3

返回 [1,3,2].

/** * Definition of TreeNode: * class TreeNode { * public: *     int val; *     TreeNode *left, *right; *     TreeNode(int val) { *         this->val = val; *         this->left = this->right = NULL; *     } * } */class Solution {public:    /*     * @param root: A Tree     * @return: Inorder in ArrayList which contains node values.     */    vector<int> inorderTraversal(TreeNode * root) {        vector<int> tmp;        if(root==NULL) return tmp;        stack<TreeNode*> s;        TreeNode* cur=root;        while(!s.empty()||cur!=NULL){            if(cur!=NULL){                s.push(cur);                cur=cur->left;            }else{                cur=s.top();                tmp.push_back(cur->val);                s.pop();                cur=cur->right;            }        }        return tmp;    }};