随笔分类 -  二叉树

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剑指offer——27. 二叉搜索树与双向链表（Java版）
摘要：题目: 剑指offer的题目有挺多都挺典型的，就像这一道。不过书中的代码写的真是ugly，有很多题目LeetCode上都有，可以去LeetCode讨论区看看，经常有一些大神分享，写的代码真是高效、简洁、清晰，剑指offer上的代码不仅变量名定义又长又不知所云，让人看着就很不清晰明了，还有各种没必要的 阅读全文
posted @ 2018-09-16 00:08 丶Blank 阅读(454) 评论(0) 推荐(0)
Lowest Common Ancestor of a Binary Tree——Leetcode
摘要：Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree.According to thedefinition of LCA on Wikipedia: “The lowest ... 阅读全文
posted @ 2015-09-20 16:39 丶Blank 阅读(206) 评论(0) 推荐(0)
Count Complete Tree Nodes ——LeetCode
摘要：Given acompletebinary tree, count the number of nodes.Definition of a complete binary tree fromWikipedia:In a complete binary tree every level, except... 阅读全文
posted @ 2015-06-25 12:33 丶Blank 阅读(175) 评论(0) 推荐(0)
Invert Binary Tree——LeetCode
摘要：Invert a binary tree. 4 / \ 2 7 / \ / \1 3 6 9to 4 / \ 7 2 / \ / \9 6 3 1Trivia:This problem was inspired bythis... 阅读全文
posted @ 2015-06-25 11:11 丶Blank 阅读(154) 评论(0) 推荐(0)
Binary Tree Preorder Traversal —— LeetCode
摘要：Given a binary tree, return thepreordertraversal of its nodes' values.For example:Given binary tree{1,#,2,3}, 1 \ 2 / 3return[1,2,3].Not... 阅读全文
posted @ 2015-05-24 20:28 丶Blank 阅读(98) 评论(0) 推荐(0)
Unique Binary Search Trees——LeetCode
摘要：Givenn, how many structurally uniqueBST's(binary search trees) that store values 1...n?For example,Givenn= 3, there are a total of 5 unique BST's. 1... 阅读全文
posted @ 2015-05-01 14:06 丶Blank 阅读(166) 评论(0) 推荐(0)
Binary Tree Inorder Traversal ——LeetCode
摘要：Given a binary tree, return theinordertraversal of its nodes' values.For example:Given binary tree{1,#,2,3}, 1 \ 2 / 3return[1,3,2].Note... 阅读全文
posted @ 2015-04-23 21:40 丶Blank 阅读(166) 评论(0) 推荐(0)
Validate Binary Search Tree——LeetCode
摘要：Given a binary tree, determine if it is a valid binary search tree (BST).Assume a BST is defined as follows:The left subtree of a node contains only n... 阅读全文
posted @ 2015-04-22 22:40 丶Blank 阅读(293) 评论(0) 推荐(0)
Binary Tree Zigzag Level Order Traversal——LeetCode
摘要：Given a binary tree, return thezigzag level ordertraversal of its nodes' values. (ie, from left to right, then right to left for the next level and al... 阅读全文
posted @ 2015-04-21 21:47 丶Blank 阅读(159) 评论(0) 推荐(0)
Construct Binary Tree from Preorder and Inorder Traversal——LeetCode
摘要：Given preorder and inorder traversal of a tree, construct the binary tree.题目大意：给定一个二叉树的前序和中序序列，构建出这个二叉树。解题思路：跟中序和后序一样，在先序中取出根节点，然后在中序中找到根节点，划分左右子树，递归构... 阅读全文
posted @ 2015-04-21 15:42 丶Blank 阅读(153) 评论(0) 推荐(0)
Construct Binary Tree from Inorder and Postorder Traversal——LeetCode
摘要：Given inorder and postorder traversal of a tree, construct the binary tree.题目大意：给定一个二叉树的中序和后续序列，构建出这个二叉树。解题思路：首先后序序列的最后一个是根节点，然后在中序序列中找到这个节点，中序序列中这个节点... 阅读全文
posted @ 2015-04-21 15:26 丶Blank 阅读(165) 评论(0) 推荐(0)
Convert Sorted Array to Binary Search Tree——LeetCode
摘要：Given an array where elements are sorted in ascending order, convert it to a height balanced BST.题目大意：给定一个升序序列的数组，将其转换为二叉搜索树。解题思路：数组中间元素是根元素，根元素将数组划分为... 阅读全文
posted @ 2015-04-20 21:28 丶Blank 阅读(140) 评论(0) 推荐(0)
Flatten Binary Tree to Linked List ——LeetCode
摘要：Given a binary tree, flatten it to a linked list in-place.For example,Given 1 / \ 2 5 / \ \ 3 4 6The flattened t... 阅读全文
posted @ 2015-04-13 20:36 丶Blank 阅读(116) 评论(0) 推荐(0)
Binary Search Tree Iterator——LeetCode
摘要：Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST.Callingnext()will return the next... 阅读全文
posted @ 2015-04-13 19:53 丶Blank 阅读(140) 评论(0) 推荐(0)
Sum Root to Leaf Numbers——LeetCode
摘要：Given a binary tree containing digits from0-9only, each root-to-leaf path could represent a number.An example is the root-to-leaf path1->2->3which rep... 阅读全文
posted @ 2015-04-05 23:17 丶Blank 阅读(115) 评论(0) 推荐(0)
Symmetric Tree——LeetCode
摘要：Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).For example, this binary tree is symmetric: 1 / \ ... 阅读全文
posted @ 2015-03-22 18:07 丶Blank 阅读(166) 评论(0) 推荐(0)
Binary Tree Level Order Traversal II——LeetCode
摘要：Given a binary tree, return thebottom-up level ordertraversal of its nodes' values. (ie, from left to right, level by level from leaf to root).For exa... 阅读全文
posted @ 2015-03-22 14:01 丶Blank 阅读(167) 评论(0) 推荐(0)
Balanced Binary Tree——LeetCode
摘要：Given a binary tree, determine if it is height-balanced.For this problem, a height-balanced binary tree is defined as a binary tree in which the depth... 阅读全文
posted @ 2015-03-22 12:07 丶Blank 阅读(169) 评论(0) 推荐(0)
Minimum Depth of Binary Tree ——LeetCode
摘要：Given a binary tree, find its minimum depth.The minimum depth is the number of nodes along the shortest path from the root node down to the nearest le... 阅读全文
posted @ 2015-03-22 00:18 丶Blank 阅读(202) 评论(0) 推荐(0)
二叉树遍历
摘要：题目描述：二叉树的前序、中序、后序遍历的定义：前序遍历：对任一子树，先访问跟，然后遍历其左子树，最后遍历其右子树；中序遍历：对任一子树，先遍历其左子树，然后访问根，最后遍历其右子树；后序遍历：对任一子树，先遍历其左子树，然后遍历其右子树，最后访问根。给定一棵二叉树的前序遍历和中序遍历，求其后序遍历（提示：给定前序遍历与中序遍历能够唯一确定后序遍历）。输入：两个字符串，其长度n均小于等于26。第一行为前序遍历，第二行为中序遍历。二叉树中的结点名称以大写字母表示：A，B，C....最多26个结点。输出：输入样例可能有多组，对于每组测试样例，输出一行，为后序遍历的字符串。样例输入：ABCBACFDX 阅读全文
posted @ 2013-03-03 17:45 丶Blank 阅读(243) 评论(0) 推荐(0)

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