题目: Given preorder and inorder traversal of a tree, construct the binary tree. Note:You may assume that duplicates do not exist in the tree. 说明: 1)二叉树可空 2)思路:a.根据前序遍历的特点, 知前序序列(PreSequence)的首个元素(PreSequence[0])为二叉树的根(root),  然后在中序序列(InSequence)中查找此根(…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 递归 日期 题目地址:https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/description/ 题目描述 Given preorder and inorder traversal of a tree, construct t…

Given preorder and inorder traversal of a tree, construct the binary tree. Note:You may assume that duplicates do not exist in the tree. For example, given preorder = [,,,,] inorder = [,,,,] Return the following binary tree: / \ / \ 前序.中序遍历得到二叉树,可以知道…

题目描述: 给定一颗二叉树,使用非递归方法实现二叉树的中序遍历 题目来源: http://oj.leetcode.com/problems/binary-tree-inorder-traversal/ 题目分析: 递归到非递归的转换.使用栈描述递归的调用过程,while循环体计算递归程序的计算部分.因为每次while循环只能处理一次递归调用,使用标记记录栈中节点的计算痕迹,例如:用tag记录当前根的调用记录,当根的左右子树均未调用时,令tag值为0,当根的左子树已经调用过时,令tag值为1. 时…

给定一棵树的前序遍历与中序遍历,依据此构造二叉树.注意:你可以假设树中没有重复的元素.例如,给出前序遍历 = [3,9,20,15,7]中序遍历 = [9,3,15,20,7]返回如下的二叉树:    3   / \  9  20    /  \   15   7详见:https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/description/ Java实现: /** *…

要求:通过二叉树的前序和中序遍历序列构建一颗二叉树 代码如下: struct TreeNode { int val; TreeNode *left; TreeNode *right; TreeNode(int x): val(x),left(NULL), right(NULL) {} }; typedef vector<int>::iterator Iter; TreeNode *buildTree(vector<int> &preorder, vector<int&…

题目: 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? 说明:1)下面有两种实现:递归(Recursive )与非递归(迭代iterati…

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? confused what "{1,#,2,3}" means? > r…

非递归的中序遍历,要用到一个stack class Solution { public: vector<int> inorderTraversal(TreeNode* root) { vector<int> ret; if(!root) return ret; //a(ret) stack<TreeNode*> stk; stk.push(root); //ahd(root) //a(stk) //dsp TreeNode* p=root; while(p->le…

144. Binary Tree Preorder Traversal 前序的非递归遍历:用堆来实现 如果把这个代码改成先向堆存储左节点再存储右节点,就变成了每一行从右向左打印 如果用队列替代堆,并且先存储左节点,再存储右节点,就变成了逐行打印 class Solution { public: vector<int> preorderTraversal(TreeNode* root) { vector<int> result; if(root == NULL) return res…