题目 The lowest common ancestor (LCA) of two nodes U and V in a tree is the deepest node that has both U and V as descendants. Given any two nodes in a binary tree, you are supposed to find their LCA. Input Specification: Each input file contains one t…

1151 LCA in a Binary Tree (30 分) The lowest common ancestor (LCA) of two nodes U and V in a tree is the deepest node that has both U and V as descendants. Given any two nodes in a binary tree, you are supposed to find their LCA. Input Specification:…

题目描述 The lowest common ancestor (LCA) of two nodes U and V in a tree is the deepest node that has both U and V as descendants.Given any two nodes in a binary tree, you are supposed to find their LCA. 最小共同祖先(LCA)是一棵树中两个节点U和V最深的那个公共父节点.要求给一棵树,以及两个节点,请你…

The lowest common ancestor (LCA) of two nodes U and V in a tree is the deepest node that has both U and V as descendants. Given any two nodes in a binary tree, you are supposed to find their LCA. Input Specification: Each input file contains one test…

The lowest common ancestor (LCA) of two nodes U and V in a tree is the deepest node that has both U and V as descendants. Given any two nodes in a binary tree, you are supposed to find their LCA. Input Specification: Each input file contains one test…

https://pintia.cn/problem-sets/994805342720868352/problems/1038430130011897856 The lowest common ancestor (LCA) of two nodes U and V in a tree is the deepest node that has both U and V as descendants. Given any two nodes in a binary tree, you are sup…

The lowest common ancestor (LCA) of two nodes U and V in a tree is the deepest node that has both U and V as descendants. Given any two nodes in a binary tree, you are supposed to find their LCA. Input Specification: Each input file contains one test…

给定先序中序遍历的序列,可以确定一颗唯一的树 先序遍历第一个遍历到的是根,中序遍历确定左右子树 查结点a和结点b的最近公共祖先,简单lca思路: 1.如果a和b分别在当前根的左右子树,当前的根就是最近祖先 2.如果根等于a或者根等于b了,根就是最近祖先:判断和a等还是和b等就行了 3.如果都在左子树上,递归查左子树就可以了.这里找到左子树的边界和根(通过先序中序序列) 4.如果都在右子树上,递归查右子树. 代码1:不建树的做法,参考柳婼blog~ #include<bits/stdc++.h>…

Source: PAT A1151 LCA in a Binary Tree (30 分) Description: The lowest common ancestor (LCA) of two nodes U and V in a tree is the deepest node that has both U and V as descendants. Given any two nodes in a binary tree, you are supposed to find their…

题目地址 https://pta.patest.cn/pta/test/16/exam/4/question/669 5-7 Complete Binary Search Tree   (30分) 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 w…

1064 Complete Binary Search Tree (30 分)   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 right subtree of a…

PAT甲级:1064 Complete Binary Search Tree (30分) 题干 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 right subtre…

7-4 Cartesian Tree (30分)   A Cartesian tree is a binary tree constructed from a sequence of distinct numbers. The tree is heap-ordered, and an inorder traversal returns the original sequence. For example, given the sequence { 8, 15, 3, 4, 1, 5, 12, 1…

LCA in a Binary Tree PAT-1151 本题的困难在于如何在中序遍历和前序遍历已知的情况下找出两个结点的最近公共祖先. 可以利用据中序遍历和前序遍历构建树的思路,判断两个结点在根节点的左右子树,依次递归找到最近祖先 import java.util.HashMap; import java.util.Map; import java.util.Scanner; import java.util.TreeMap; /** * @Author WaleGarrett * @Dat…

The lowest common ancestor (LCA) of two nodes U and V in a tree is the deepest node that has both U and V as descendants. Given any two nodes in a binary tree, you are supposed to find their LCA. Input Specification: Each input file contains one test…

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 right subtree of a node contains only nodes with keys greate…

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 right subtree of a node contains only nodes with keys greate…

236. Lowest Common Ancestor of a Binary Tree /** * 基础版 * 给定p,q都是在树中 * 有两种情况: * 1. p和q分布在LCA的两侧 * 2. p和q在同一侧(p是q的祖先 或者是 q是p的祖先) * 先考虑第一种情况,例如: * 1 * / \ * 2 4 * 2和4的LCA是1,向下递归返回时,2返回2,4返回4,1接受到的left和right的返回值都存在值,那么就返回自己 * 也就是说=> 只要找到目标节点,就往上返回该节点 * -…

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 (≤) which is the total number of nodes in the tree -- and he…

题意:输入一个正整数N(<=1000),接着输入N个非负整数(<=2000),输出完全二叉树的层次遍历. AAAAAccepted code: #define HAVE_STRUCT_TIMESPEC #include<bits/stdc++.h> using namespace std; ]; ]; int cnt; int n; void dfs(int x){ if(x>n) return; dfs(x*); tree[x]=a[++cnt]; dfs(x*+); }…

题意: 输入一个正整数N(<=100),接着输入N行每行包括0~N-1结点的左右子结点,接着输入一行N个数表示数的结点值.输出这颗二叉排序树的层次遍历. AAAAAccepted code: #define HAVE_STRUCT_TIMESPEC #include<bits/stdc++.h> using namespace std; pair<]; ]; ; ]; void dfs(int x){ ) return ; dfs(a[x].first); ans[x]=b[++c…

题意:根据前序和中序建立树,寻找两个点的LCA. 我在之前的博客中写了关于LCA的多种求法. https://www.cnblogs.com/yy-1046741080/p/11505547.html.  在建树的过程中,建立深度和parent,来寻找LCA. 该题目的数据有一定的欺诈性,它给你结点数据是1-8,如果没有仔细看清题目,那么很有可能定义一个 node tree[10005]的数组,但是题目并没有说数据范围在1-10000内. 经过测试,如果你将范围定义稍微大一点,还是能全过的: 我…

题意: 输入一个正整数N(<=20),代表结点个数(0~N-1),接着输入N行每行包括每个结点的左右子结点,'-'表示无该子结点,输出是否是一颗完全二叉树,是的话输出最后一个子结点否则输出根节点. trick: 用char输入子结点没有考虑两位数的结点…

题意: 输入一个正整数N(<=10),接着输入0~N-1每个结点的左右儿子结点,输出这颗二叉树的反转的层次遍历和中序遍历. AAAAAccepted code: #define HAVE_STRUCT_TIMESPEC #include<bits/stdc++.h> using namespace std; ][]; ]; void bfs(int r){ queue<int>q; q.push(r); cout<<r; while(!q.empty()){ in…

题外话:考试的时候花了一个小时做了27分,由于Siblings这个单词不知道意思,所以剩下的3分就没去纠结了,后来发现单词是兄弟的意思,气哭~~ 这道题的麻烦之处在于如何从一个字符串中去找数字.先首先我们需要整行读取(包括空格),这个我自己写另一个函数,挺好用的: string mygets() { ]; fgets(str,sizeof(str),stdin); int len = strlen(str); ]==] = '\0'; return str; } 用的时候只要 string st…

leetcode面试准备:Lowest Common Ancestor of a Binary Search Tree & Binary Tree 1 题目 Binary Search Tree的LCA Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST. According to the definition of LCA on Wikiped…

本文同步发布在CSDN:https://blog.csdn.net/weixin_44385565/article/details/90577042 1102 Invert a Binary Tree (25 分)   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…

此文章同步发布在CSDN上:https://blog.csdn.net/weixin_44385565/article/details/90317830   1110 Complete Binary Tree (25 分)   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…

Source: PAT A1110 Complete Binary Tree (25 分) Description: 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 (…

Source: PAT A1102 Invert a Binary Tree (25 分) Description: 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…