Design an algorithm and write code to serialize and deserialize a binary tree. Writing the tree to a file is called 'serialization' and reading back from the file to reconstruct the exact same binary tree is 'deserialization'. There is no limit of ho…

Design an algorithm and write code to serialize and deserialize a binary tree. Writing the tree to a file is called 'serialization' and reading back from the file to reconstruct the exact same binary tree is 'deserialization'. There is no limit of ho…

描述 给出一棵二叉树,返回其节点值的层次遍历(逐层从左往右访问) 样例 给一棵二叉树 {3,9,20,#,#,15,7} : 3 / \ 9 20 / \ 15 7 返回他的分层遍历结果: [ [3], [9,20], [15,7] ] 挑战 挑战1:只使用一个队列去实现它 挑战2:用BFS算法来做 代码 GitHub 的源代码,请访问下面的链接: https://github.com/cwiki-us/java-tutorial/blob/master/src/test/java/com/os…

Given a binary tree, find the maximum path sum from root. The path may end at any node in the tree and contain at least one node in it. 给一棵二叉树,找出从根节点出发的路径中,和最大的一条. 这条路径可以在任何二叉树中的节点结束,但是必须包含至少一个点(也就是根了). /** * Definition of TreeNode: * public class Tr…

Given a binary tree, return all root-to-leaf paths.Example Given the following binary tree: 1 /   \2     3 \  5 All root-to-leaf paths are: [  "1->2->5",  "1->3"] LeetCode上的原题,请参见我之前的博客Binary Tree Paths. 解法一: class Solution {…

Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. Example Given the below binary tree: 1 / \ 2 3 return 6. For this problem we need to think about the problem in this way. Now we want the largest sum…

Binary Tree Inorder Traversal Given a binary tree, return the inorder traversal of its nodes' values. Example Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,3,2]. For in-order traversal we all know that firstly we want to go to the lowest level and…

Binary Tree Paths Given a binary tree, return all root-to-leaf paths. Given the following binary tree: 1 / \ 2 3 \ 5 All root-to-leaf paths are: [ "1->2->5", "1->3" ] As mentioned in the problem we want to get all root-to-leaf…

Given a binary tree, return the preorder traversal of its nodes' values. Given: 1 / \ 2 3 / \ 4 5 return [1,2,4,5,3]. Thinking: For this problem, you need to think about using recursive or non-recursive methods. As recursive method, we should think t…

Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return [ [3], [9,20], [15,7] ] For the problem given I decided to use BFS,…