题: 解: 这道题考的是如何找出一个二叉树里所有的序列. 我的思路是先从根节点开始遍历,找出所有的子节点,因为每个子节点只有一个父节点,再根据每个子节点向上遍历找出所有的序列,再判断序列的总和. 这样解效率不高,但暂时只能想到这样.如果您有其余的解法,期望告知. 代码: package com.lintcode; import java.util.ArrayList; import java.util.Collections; import java.util.Enumeration; impo…

Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example:Given the below binary tree, 1 / \ 2 3 Return6. 思路:题目中说明起始节点可以是任意节点,所以,最大的路径和不一样要经过root,可以是左子树中某一条,或者是右子树中某一条,当然也可能是经过树的根节点root的.递归式是应该是这三…

给定二叉树,找到它的最大深度. 最大深度是从根节点到最远叶节点的最长路径上的节点数. 注意:叶子是没有子节点的节点. Example: Given binary tree [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 return its depth = 3. class TreeNode { int val; TreeNode left; TreeNode right; TreeNode(int x) { val = x; } } class Sol…

You are given a binary tree in which each node contains an integer value. Find the number of paths that sum to a given value. The path does not need to start or end at the root or a leaf, but it must go downwards (traveling only from parent nodes to…

If the depth of a tree is smaller than 5, then this tree can be represented by a list of three-digits integers. For each integer in this list: The hundreds digit represents the depth D of this node, 1 <= D <= 4. The tens digit represents the positio…

数据结构中一直对二叉树不是很了解,今天趁着这个时间整理一下 许多实际问题抽象出来的数据结构往往是二叉树的形式,即使是一般的树也能简单地转换为二叉树,而且二叉树的存储结构及其算法都较为简单,因此二叉树显得特别重要.     二叉树(BinaryTree)是n(n≥0)个结点的有限集,它或者是空集(n=0),或者由一个根结点及两棵互不相交的.分别称作这个根的左子树和右子树的二叉树组成.     这个定义是递归的.由于左.右子树也是二叉树, 因此子树也可为空树.下图中展现了五种不同基本形态的二叉树.…

Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example:Given the below binary tree, 1 / \ 2 3 Return 6. 这道求二叉树的最大路径和是一道蛮有难度的题,难就难在起始位置和结束位置可以为任意位置,我当然是又不会了,于是上网看看大神们的解法,看了很多人的都没太看明白,最后发现了网友Yu's…

Given a non-empty binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The path must contain at least one node and doe…

首先定义一个节点类,包含三个成员变量,分别是节点值,左指针,右指针,如下代码所示: class Node(object): def __init__(self, value): self.value = value self.left = None self.right = None 接下来就是二叉树的相关工作: 1)初始化一棵二叉树 class Solution(object): def __init__(self): root = Node(6) B = Node(4) root.left…

Given a binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The path does not need to go through the root. For exampl…