Big binary tree Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 670    Accepted Submission(s): 235 Problem Description You are given a complete binary tree with n nodes. The root node is numbere…

Big binary tree Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 597    Accepted Submission(s): 207 Problem Description You are given a complete binary tree with n nodes. The root node is numbere…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=6161 题意: 题目是给一棵完全二叉树,从上到下从左到右给每个节点标号,每个点有权值,初始权值为其标号,然后有两种操作: 1.把u点权值改为x 2.查询所有经过u点的路径中,路径上的点权和最大. 节点有n个,修改有m个,n<=1e8 ,m<= 1e5 解法:现场队友过的,orz,来自队友的思路. 我们首先对于一个点,如果没有访问我们不把它建出来,相反访问了就把它建出来,这个题的最小的子问题就是计算一…

判断一棵树是否是平衡树,即左右子树的深度相差不超过1. 我们可以回顾下depth函数其实是Leetcode 104 Maximum Depth of Binary Tree 二叉树 /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL…

[Leetcode] Maximum and Minimum Depth of Binary Tree 二叉树的最小最大深度 (最小有3种解法) 描述 解析 递归深度优先搜索 当求最大深度时,我们只要在左右子树中取较大的就行了. 然而最小深度时,如果左右子树中有一个为空会返回0,这时我们是不能算做有效深度的. 所以分成了三种情况,左子树为空,右子树为空,左右子树都不为空.当然,如果左右子树都为空的话,就会返回1. 广度优先搜索(类似层序遍历的思想) 递归解法本质是深度优先搜索,但因为我们是求最小…

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. 给一个二叉树,找出它的最小深度.最小深度是从根节点向下到最近的叶节点的最短路径,就是最短路径的节点个数. 解法1:DFS 解法2: BFS Java: DFS, Time Comp…

Given a binary tree, you need to compute the length of the diameter of the tree. The diameter of a binary tree is the length of the longest path between any two nodes in a tree. This path may or may not pass through the root. Example:Given a binary t…

Serialization is the process of converting a data structure or object into a sequence of bits so that it can be stored in a file or memory buffer, or transmitted across a network connection link to be reconstructed later in the same or another comput…

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 and w…

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. 二叉树的经典问题之最小深度问题就是就最短路径的节点个数,还是用深度优先搜索DFS来完成,万能的递归啊...请看代码: /** * Definition for binary tre…

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. 求二叉树的最大深度问题用到深度优先搜索DFS,递归的完美应用,跟求二叉树的最小深度问题原理相同.代码如下: C++ 解法一: class Solution { public: in…

[LeetCode]Minimum Depth of Binary Tree 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. 递归和非递归,此提比较简单.广度优先遍历即可.关键之处就在于如何保持访问深度. 下面是4种代码: im…

Given a binary tree where every node has a unique value, and a target key k, find the value of the nearest leaf node to target k in the tree. Here, nearest to a leaf means the least number of edges travelled on the binary tree to reach any leaf of th…

Given a non-empty special binary tree consisting of nodes with the non-negative value, where each node in this tree has exactly two or zero sub-node. If the node has two sub-nodes, then this node's value is the smaller value among its two sub-nodes.…

Given a binary tree, write a function to get the maximum width of the given tree. The width of a tree is the maximum width among all levels. The binary tree has the same structure as a full binary tree, but some nodes are null. The width of one level…

Given a non-empty binary tree, return the average value of the nodes on each level in the form of an array. Example 1: Input: 3 / \ 9 20 / \ 15 7 Output: [3, 14.5, 11] Explanation: The average value of nodes on level 0 is 3, on level 1 is 14.5, and o…

Given a binary tree, return the values of its boundary in anti-clockwise direction starting from root. Boundary includes left boundary, leaves, and right boundary in order without duplicate nodes. Left boundary is defined as the path from root to the…

Given a binary tree, you need to compute the length of the diameter of the tree. The diameter of a binary tree is the length of the longestpath between any two nodes in a tree. This path may or may not pass through the root. Example:Given a binary tr…

We are given a binary tree (with root node root), a target node, and an integer value K. Return a list of the values of all nodes that have a distance K from the target node.  The answer can be returned in any order. Example 1: Input: root = [3,5,1,6…

  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 p and q as the lowest node in T that has both p and…

要求:此题正好和Maximum Depth of Binary Tree一题是相反的,即寻找二叉树的最小的深度值:从根节点到最近的叶子节点的距离. 结题思路:和找最大距离不同之处在于:找最小距离要注意(l<r)? l+1:r+1的区别应用,因为可能存在左右子树为空的情况,此时值就为0,但显然值是不为0的(只有当二叉树为空才为0),所以,在这里注意一下即可! 代码如下: struct TreeNode { int val; TreeNode *left; TreeNode *right; Tree…

要求:求二叉树的深度(二叉树的深度为最远叶子节点到根节点的距离,即根节点到最远叶子节点的距离) 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. 有两种求解的思路,一种采用DFS的思想,一种采用BFS的思想,如下代码所示: str…

题目: Given a non-empty binary tree, return the average value of the nodes on each level in the form of an array. Example 1: Input: 3 / \ 9 20 / \ 15 7 Output: [3, 14.5, 11] Explanation: The average value of nodes on level 0 is 3, on level 1 is 14.5, a…

Given a binary tree, you need to compute the length of the diameter of the tree. The diameter of a binary tree is the length of the longest path between any two nodes in a tree. This path may or may not pass through the root. Example:Given a binary t…

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. 此题是经典的求二叉树深度深度题目,可采用递归的方式,以此求每个节点的左子树深度和右子树深度,然后返回该节点左右子树深度最大的那个即为该节点的深度 具体代码如下: /** * Defi…

［抄题］: Given a non-empty binary tree, return the average value of the nodes on each level in the form of an array. Example 1: Input: 3 / \ 9 20 / \ 15 7 Output: [3, 14.5, 11] Explanation: The average value of nodes on level 0 is 3, on level 1 is 14.5,…

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. 方法一: 层次遍历,整棵树的层数,即二叉树的最大深度.主体的代码还是在层次遍历的基础上改成的. /** * Definition for binary tree * struct…

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. 方法一: 层次遍历.主体的思想不变,程序的主体结构也不变,具体遍历过程参照二叉树的层次遍历.关键在于终止条件,在某一层中,节点遍历的顺序是从左往右的,若是最短路径出现在该层中,则其…

题目: Given a non-empty special binary tree consisting of nodes with the non-negative value, where each node in this tree has exactly two or zero sub-node. If the node has two sub-nodes, then this node's value is the smaller value among its two sub-nod…

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. Hide Tags Tree Depth-first Search       这题是找二叉树的最小深度,这是广度搜索比较好吧,为啥提示给的是 深度优先呢. 判断树是否为空 将ro…