feng_zhiyu的博客

Given a binary tree, return the inorder traversal of its nodes' values.Example:Input: [1,null,2,3] 1 \ 2 / 3Output: [1,3,2]Follow up: Recursive solution is trivial, ...

前序遍历和中序遍历树构造二叉树 """Definition of TreeNode:""" class TreeNode: def __init__(self, val): self.val = val self.left, self.right = None, None class Solution: """ @...

题目链接Given a syntax tree (binary), you are supposed to output the corresponding infix expression, with parentheses reflecting the precedences of the operators.Input Specification:Each input file ...

代码【递归】：class Solution {public: bool VerifySquenceOfBST(vector<int> sequence) { if(sequence.empty()) { return false; } int len=sequence.size(); //...

题目链接题目描述从上往下打印出二叉树的每个节点，同层节点从左至右打印。思路：bfs代码：/*struct TreeNode { int val; struct TreeNode *left; struct TreeNode *right; TreeNode(int x) : val(x), left(NULL), right(NULL) { }};*/class Soluti...

题目链接题目描述请实现一个函数，用来判断一颗二叉树是不是对称的。注意，如果一个二叉树同此二叉树的镜像是同样的，定义其为对称的。思路：判断二叉树是否对称，也就是比较左右子树是否对称，那么递归比较左右子树即可。代码：/*struct TreeNode { int val; struct TreeNode *left; struct TreeNode *right; T...

题目链接题目描述操作给定的二叉树，将其变换为源二叉树的镜像。输入描述:二叉树的镜像定义：源二叉树 8 / \ 6 10 / \ / \ 5 7 9 11 镜像二叉树 8 / \ 10 6 / \ / \ 11 9 7 5思路：若...

题目描述输入某二叉树的前序遍历和中序遍历的结果，请重建出该二叉树。假设输入的前序遍历和中序遍历的结果中都不含重复的数字。例如输入前序遍历序列{1,2,4,7,3,5,6,8}和中序遍历序列{4,7,2,1,5,3,8,6}，则重建二叉树并返回。二叉树遍历方式：前序序列：先访问根节点，再访问左子节点，最后访问右子节点。中序序列：先访问左子节点，再访问根节点，最后访问右子节点。后序序列：先访问左子节点...

题目链接Suppose that all the keys in a binary tree are distinct positive integers. A unique binary tree can be determined by a given pair of postorder and inorder traversal sequences. And it is a simple s...

题目链接Suppose that all the keys in a binary tree are distinct positive integers. Given the postorder and inorder traversal sequences, you are supposed to output the level order traversal sequence of the...

题目链接 Given two binary trees, write a function to check if they are the same or not.Two binary trees are considered the same if they are structurally identical and the nodes have the same value.Ex...

给定一棵二叉树的中序遍历和前序遍历，请你先将树做个镜面反转，再输出反转后的层序遍历的序列。所谓镜面反转，是指将所有非叶结点的左右孩子对换。这里假设键值都是互不相等的正整数。输入格式：输入第一行给出一个正整数N（<=30），是二叉树中结点的个数。第二行给出其中序遍历序列。第三行给出其前序遍历序列。数字间以空格分隔。输出格式：在一行中输出该树反转后的层序遍历的序列。数字间以1个空...

给定一棵二叉树的后序遍历和中序遍历，请你输出其层序遍历的序列。这里假设键值都是互不相等的正整数。输入格式：输入第一行给出一个正整数N（<=30），是二叉树中结点的个数。第二行给出其后序遍历序列。第三行给出其中序遍历序列。数字间以空格分隔。输出格式：在一行中输出该树的层序遍历的序列。数字间以1个空格分隔，行首尾不得有多余空格。输入样例： 7 2 3 1 5 7 6 4 ...

时间限制：1.0s 内存限制：256.0MB 问题描述 　　摩尔斯电码破译。类似于乔林教材第213页的例6.5，要求输入摩尔斯码，返回英文。请不要使用”zylib.h”，只能使用标准库函数。用’ * ‘表示’ . ‘，中间空格用’ | ‘表示，只转化字符表。　　摩尔斯码定义见： 提示 　　清橙进行评测时，输入是以EOF结尾的，而不是换行符。（EOF不是一个字符，“以EOF结尾”

链接：https://vjudge.net/problem/UVA-839题意：输入一个树状天平，根据力矩规则判断是否平衡。 Wl*Dl=Wr*Dr 先序遍历输入，每个天平的格式:Wl,Dl,Wr,Dr Wl或Wr=0时，表示输入一个子天平，接下来描述这个天平，当两者都为0，左右天平依次描述。分析：直接在输入的时候判断子天平是否平衡，并更新子天平的重量（此处用到 了 C++中的引用） 紫书P15

二叉树遍历

题目链接Given a tree, you are supposed to tell if it is a complete binary tree.Input Specification:Each input file contains one test case. For each case, the first line gives a positive integer N (≤...

题目链接An inorder binary tree traversal can be implemented in a non-recursive way with a stack. For example, suppose that when a 6-node binary tree (with the keys numbered from 1 to 6) is traversed, the...

题目链接A Binary Search Tree (BST) is recursively defined as a binary tree which has the following properties:The left subtree of a node contains only nodes with keys less than the node's key. The rig...

题目链接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 tu...

题目链接A Binary Search Tree (BST) is recursively defined as a binary tree which has the following properties:The left subtree of a node contains only nodes with keys less than the node's key. The rig...

题目链接题目描述输入两棵二叉树A，B，判断B是不是A的子结构。（ps：我们约定空树不是任意一个树的子结构）思路：例如图中的两棵二叉树，由于A中有一部分子树的结构和B是一样的，因此B是A的子结构。要查找树A中是否存在和树B结构一样的子树，可以分成两步：第一步在树A中找到和B的根节点的值一样的结点R； 第二步再判断树A中以R为根结点的子树是不是包含和树B一样的结构。第一...

题目链接In computer science, a heap is a specialized tree-based data structure that satisfies the heap property: if P is a parent node of C, then the key (the value) of P is either greater than or equal...

题目链接A Binary Search Tree (BST) is recursively defined as a binary tree which has the following properties:The left subtree of a node contains only nodes with keys less than the node's key. The ri...

思路：建立二叉树，左旋90度输出可以用一个逆中序遍历和一个参数记录当前节点所在层数的方式来输出#include <iostream>#include <cstring>#include <stdlib.h>#include <stack>#include <cstdio>using namespace std;t...