题目: 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 of the two subtrees of every node never differ by more than 1. 代码: /** * Definition for a bina…

平衡的二叉树的定义都是递归的定义,所以,用递归来解决问题,还是挺容易的额. 本质上是递归的遍历二叉树. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 给定一个二叉树,判定他是不是高度平衡的二叉树. 对于这个问题,每个节点的两个子树的深度不会相差超过1,那么这样的二叉树就是一个平衡的二叉树 +++++++++++++++++++++++++++++++++++++++++++++…

题目: Invert Binary Tree Total Accepted: 20346 Total Submissions: 57084My Submissions Question Solution  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:…

题目: 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. 代码: /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode…

题目: 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 leaf node. 代码: /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode…

题目: Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree. According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two nodes v and w as the lowest node in T that has both v a…

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 of the two subtrees of every node never differ by more than 1. 思路: 我居然在这道题上卡了一个小时.关键是对于平衡的定义,我开始理解…

Balanced Binary Tree Better Solution [LeetCode] https://leetcode.com/submissions/detail/40087813/ Total Accepted: 72203 Total Submissions: 225370 Difficulty: Easy Question Given a binary tree, determine if it is height-balanced. For this problem, a h…

[114-Flatten Binary Tree to Linked List(二叉树转单链表)] [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, flatten it to a linked list in-place. For example, Given 1 / \ 2 5 / \ \ 3 4 6 The flattened tree should look like: 1 \ 2 \ 3 \ 4 \ 5 \ 6 题目…

Balanced Binary Tree [数据结构和算法]全面剖析树的各类遍历方法 描述 解析 递归分别判断每个节点的左右子树 该题是Easy的原因是该题可以很容易的想到时间复杂度为O(n^2)的方法.即按照定义,判断根节点左右子树的高度是不是相差1,递归判断左右子树是不是平衡的. 根据深度判断左右子树是否平衡 在计算树的高度的同时判断该树是不是平衡的. 即,先判断子树是不是平衡的,若是,则返回子树的高度:若不是,则返回一个非法的数字,如负数. 当一个节点是左右子树有一个不是平衡二叉树则不必继…