遍历二叉树   traversing binary tree 线索二叉树 threaded binary tree 线索链表 线索化 1. 二叉树3个基本单元组成:根节点.左子树.右子树 以L.D.R分别表示遍历左子树.访问根节点.遍历右子树 可能的情况6种 排列A3 2 LDR LRD DLR DRL RLD RDL 若限定先左后右 LDR LRD  中根序遍历  后根序遍历 DLR  先根序遍历 先/中/后 序遍历…

Given n points on a 2D plane, find the maximum number of points that lie on the same straight line. Example Given 4 points: (1,2), (3,6), (0,0), (1,3). The maximum number is 3. LeeCode上的原题,可参见我之前的博客Invert Binary Tree 翻转二叉树. 解法一: // Recursion class So…

[104-Maximum Depth of Binary Tree(二叉树的最大深度)] [LeetCode-面试算法经典-Java实现][全部题目文件夹索引] 原题 Given a binary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node. 题目大意 给…

Given a binary tree, find all leaves and then remove those leaves. Then repeat the previous steps until the tree is empty. Example: Given binary tree 1 / \ 2 3 / \ 4 5 Returns [4, 5, 3], [2], [1]. Explanation: 1. Remove the leaves [4, 5, 3] from the…

One way to serialize a binary tree is to use pre-oder traversal. When we encounter a non-null node, we record the node's value. If it is a null node, we record using a sentinel value such as #. _9_ / \ 3 2 / \ / \ 4 1 # 6 / \ / \ / \ # # # # # # For…

Given a binary tree, return all root-to-leaf paths. For example, given the following binary tree: 1 / \ 2 3 \ 5 All root-to-leaf paths are: ["1->2->5", "1->3"] 这道题给我们一个二叉树,让我们返回所有根到叶节点的路径,跟之前那道Path Sum II 二叉树路径之和之二很类似,比那道稍微简单一…

Invert a binary tree. 4 / \ 2 7 / \ / \ 1 3 6 9 to 4 / \ 7 2 / \ / \ 9 6 3 1 Trivia: This problem was inspired by this original tweet by Max Howell: Google: 90% of our engineers use the software you wrote (Homebrew), but you can’t invert a binary tre…

找到所有根到叶子的路径 深度优先搜索(DFS), 即二叉树的先序遍历. /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: vector<string> v…

Binary Tree Traversals Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3475    Accepted Submission(s): 1555 Problem Description A binary tree is a finite set of vertices that is either empty or…

对于任意一棵节点数为 n 的二叉树,NULL 指针的数目为  n+1 , 线索树就是利用这些 "浪费" 了的指针的数据结构. Definition: "A binary tree is threaded by making all right child pointers that would normally be null point to the inorder successor of the node, and all left child pointers tha…