题意:一棵n个结点的完全二叉树,初始i号结点的权值为i.有两种操作:单点修改:询问经过某个结点的路径中,权值和最大的路径的权值和是多少. 修改的时候,暴力修改到根节点的路径上的点的f(x)即可. 跟虚树的思想只是有点点像而已,实际上不是一个东西啦. 队友的代码: #include <cmath> #include <cstdio> #include <cstring> #include <iostream> #include <algorithm>…

题目: 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 思路: 按照树的先序遍历顺序把节点串联起来即可. /** * Definition for a binary tree node. * function TreeNode(va…

题目链接 题目要求: 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. 这道题难度还好.具体程序(16ms)如下: /*…

题目: Given inorder and postorder traversal of a tree, construct the binary tree. 思路: 后序序列的最后一个元素就是树根,然后在中序序列中找到这个元素(由于题目保证没有相同的元素,因此可以唯一找到),中序序列中这个元素的左边就是左子树的中序,右边就是右子树的中序,然后根据刚才中序序列中左右子树的元素个数可以在后序序列中找到左右子树的后序序列,然后递归的求解即可. /** * Definition for a binar…

题目: Given preorder and inorder traversal of a tree, construct the binary tree. 思路: 线序序列的第一个元素就是树根,然后在中序序列中找到这个元素(由于题目保证没有相同的元素,因此可以唯一找到),中序序列中这个元素的左边就是左子树的中序,右边就是右子树的中序,然后根据刚才中序序列中左右子树的元素个数可以在后序序列中找到左右子树的后序序列,然后递归的求解即可. /** * Definition for a binary…

156. Binary Tree Upside Down Add to List QuestionEditorial Solution My Submissions   Total Accepted: 18225 Total Submissions: 43407 Difficulty: Medium Contributors: Admin Given a binary tree where all the right nodes are either leaf nodes with a sibl…

题目链接 题目要求: 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 nodes with keys less than the node's key. The right subtree of a node contains only node…

平衡二叉树(Balanced Binary Tree 或 Height-Balanced Tree)又称AVL树 (a)和(b)都是排序二叉树,但是查找(b)的93节点就需要查找6次,查找(a)的93节点就需要查找3次,所以(b)的效率不高. 平衡二叉树(Balanced Binary Tree 或 Height-Balanced Tree)又称AVL树.它或者是一颗空树,或者是具有下列性质的二叉树:它的左子树和右子树的深度只差的绝对值不超过1.若将二叉树上节点的平衡因子BF(Balance F…

The following is from Max Howell @twitter: Google: 90% of our engineers use the software you wrote (Homebrew), but you can't invert a binary tree on a whiteboard so fuck off. Now it's your turn to prove that YOU CAN invert a binary tree! Input Specif…

题目: Given a binary tree, return the zigzag level order traversal of its nodes' values. (ie, from left to right, then right to left for the next level and alternate between). For example:Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return…