题目: Given a binary tree, return the postorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Recursive solution is trivial, could you do it iteratively? 题解: 递归方法代码:          ArrayList<Integer…

原题链接:https://oj.leetcode.com/problems/binary-tree-postorder-traversal/ 题目大意:后序遍历二叉树 解题思路:后序遍历二叉树的步骤:后序遍历二叉树的左子树,后序遍历二叉树的右子树,訪问根结点. 非递归实现时,用一个栈模拟遍历过程.由于訪问完左子树后訪问右子树.栈中元素要起到转向訪问其右子树的作用,可是不能像先序和中序遍历那样出栈就可以,由于根结点时最后訪问的.那么什么时候出栈呢?我们须要一个指针pre来记录前一次訪问的结点.假设…

145. Binary Tree Postorder Traversal Total Submissions: 271797 Difficulty: Hard 提交网址: https://leetcode.com/problems/binary-tree-postorder-traversal/ Given a binary tree, return the postorder traversal of its nodes' values. For example:Given binary tr…

145. 二叉树的后序遍历 145. Binary Tree Postorder Traversal 题目描述 给定一个二叉树,返回它的 后序 遍历. LeetCode145. Binary Tree Postorder Traversal 示例: 输入: [1,null,2,3] 1 \ 2 / 3 输出: [3,2,1] 进阶: 递归算法很简单,你可以通过迭代算法完成吗? Java 实现 Iterative Solution import java.util.LinkedList; impo…

Binary Tree Postorder Traversal Given a binary tree, return the postorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3},   1    \     2    /   3return [3,2,1]. Note: Recursive solution is trivial, could you do it iteratively…

Binary Tree Postorder Traversal Given a binary tree, return the postorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Recursive solution is trivial, could you do it iteratively? 解法一:递归法 /**…

详见:剑指 Offer 题目汇总索引:第6题 Binary Tree Postorder Traversal            Given a binary tree, return the postorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Recursive solution is trivial, could…

Binary Tree Preorder Traversal Given a binary tree, return the preorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,2,3]. c++版: /** * Definition for binary tree * struct TreeNode { * int val; * TreeNod…

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…

Given a binary tree, return the postorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Recursive solution is trivial, could you do it iteratively? 经典题目,求二叉树的后序遍历的非递归方法,跟前序,中序,层序一样都需要用到栈,后续的…

Given a binary tree, return the postorder traversal of its nodes' values. Example: Input: [1,null,2,3] 1 \ 2 / 3 Output: [3,2,1] Follow up: Recursive solution is trivial, could you do it iteratively? --------------------------------------------------…

翻译 给定一个二叉树.返回其兴许遍历的节点的值. 比如: 给定二叉树为 {1. #, 2, 3} 1 \ 2 / 3 返回 [3, 2, 1] 备注:用递归是微不足道的,你能够用迭代来完毕它吗? 原文 Given a binary tree, return the postorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: R…

Given a binary tree, return the postorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Recursive solution is trivial, could you do it iteratively? 经典题目,求二叉树的后序遍历的非递归方法,跟前序,中序,层序一样都需要用到栈,后序的…

题目: Given a binary tree, return the postorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Recursive solution is trivial, could you do it iteratively? 链接: http://leetcode.com/problems/binary…

Question 590. N-ary Tree Postorder Traversal Solution 题目大意:后序遍历一个树 思路: 1)递归 2)迭代 Java实现(递归): public List<Integer> postorder(Node root) { List<Integer> ansList = new ArrayList<>(); recursivePostorder(root, ansList); return ansList; } void…

Problem Link: http://oj.leetcode.com/problems/binary-tree-postorder-traversal/ The post-order-traversal of a binary tree is a classic problem, the recursive way to solve it is really straightforward, the pseudo-code is as follows. RECURSIVE-POST-ORDE…

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 迭代 日期 题目地址:https://leetcode.com/problems/binary-tree-postorder-traversal/ 题目描述 Given a binary tree, return the postorder traversal of its nodes' values. Example: Input: [1,nu…

Given a binary tree, return the postorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Recursive solution is trivial, could you do it iteratively? vector<int> postorderTraversal(TreeNode *r…

Given a binary tree, return the postorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. 后序遍历,左子树→右子树→根节点 前序遍历的非递归实现需要一个计数器,方法是需要重写一个类继承TreeNode,翁慧玉教材<数据结构:题解与拓展>P113有详细介绍,这里略.递归JAVA实现如下: public L…

Given a binary tree, return the postorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Recursive solution is trivial, could you do it iteratively? 求后序遍历,要求不使用递归. 使用栈,从后向前添加. /** * Definition…

题目: Given a binary tree, return the postorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Recursive solution is trivial, could you do it iteratively? 说明: 1) 两种实现,递归与非递归 , 其中非递归有两种方法 2)复杂度分析…

Given a binary tree, return the postorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Recursive solution is trivial, could you do it iteratively? 1.递归算法的递归定义是: 若二叉树为空,则遍历结束:否则⑴ 后序遍历左子树(递归调用…

Given a binary tree, return the postorder traversal of its nodes' values. Example: Input: [,,] \ / Output: [,,] Follow up: Recursive solution is trivial, could you do it iteratively? 方法一:利用两个栈s1,s2来实现,先将头结点入栈s1,从s1弹出栈顶节点记为cur,压入s2中,分别将cur的左右孩子压入s1,当s…

Given a binary tree, return the postorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Recursive solution is trivial, could you do it iteratively? Subscribe to see which companies asked this…

Given a binary tree, return the postorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. 思路:后序遍历是按照“左子树,右子树,根”的顺序访问元素.那么根或者其它父亲元素就要先压入栈,然后再弹出. #include <iostream> #include <algorithm> #includ…

Given a binary tree, return the postorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. 解题: 二叉树的后序遍历,比先序和中序遍历稍显麻烦一些,有兴趣可查看:二叉树先序遍历.二叉树中序遍历 后序遍历需要输出左子树后,输出右子树,最后输出当前结点.复杂的原因是,输出左右子树后,如何判断输出的结点是左还是右.…

Given a binary tree, return the postorder traversal of its nodes' values. For example:Given binary tree{1,#,2,3}, 1 \ 2 / 3 return[3,2,1]. Note: Recursive solution is trivial, could you do it iteratively? 后序遍历:左孩子->右孩子->根节点 后序遍历最关键的是利用一个指针保存前一个访问过的信…

题目: Given a binary tree, return the postorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Recursive solution is trivial, could you do it iteratively? 例如以下列出三种解法:一种迭代的和两种iterative的 import j…

Given a binary tree, return the postorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Recursive solution is trivial, could you do it iteratively? Subscribe to see which companies asked this…

Given a binary tree, return the postorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Recursive solution is trivial, could you do it iteratively? Hide Tags Tree Stack   一题后续遍历树的问题,很基础,统计哪里的…