1021 Deepest Root (25)(25 分) A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest…

1021 Deepest Root (25)(25 分)A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest…

#include <cstdio> #include <cstdlib> #include <vector> using namespace std; class Node { public: vector<int> adj; bool visited; Node() : visited(false) {} }; void reset_nodes(vector<Node>& nodes) { int len = nodes.size();…

PAT甲级1021. Deepest Root 题意: 连接和非循环的图可以被认为是一棵树.树的高度取决于所选的根.现在你应该找到导致最高树的根.这样的根称为最深根. 输入规格: 每个输入文件包含一个测试用例.对于每种情况, 第一行包含正整数N(<= 10000),它是节点的数量,因此节点从1到N编号.然后按N-1行,每个都通过给定两个相邻节点的数字来描述一个边. 输出规格: 对于每个测试用例,打印一行中最深的根.如果这样的根不是唯一的, 打印他们的数字增加的顺序.在给定的图形不是树的情况下,打…

1021. Deepest Root (25) 时间限制 1500 ms 内存限制 65536 kB 代码长度限制 16000 B 判题程序 Standard 作者 CHEN, Yue A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root t…

1021 Deepest Root (25 分)   A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest r…

https://pintia.cn/problem-sets/994805342720868352/problems/994805482919673856 A graph which is connected and acyclic can be considered a tree. The hight of the tree depends on the selected root. Now you are supposed to find the root that results in a…

http://pat.zju.edu.cn/contests/pat-a-practise/1021 无环连通图也可以视为一棵树,选定图中任意一点作为根,如果这时候整个树的深度最大,则称其为 deepest root. 给定一个图,按升序输出所有 deepest root.如果给定的图有多个连通分量,则输出连通分量的数量. 1.使用并查集判断图是否为连通的. 2.任意选取一点,做 dfs 搜索,选取其中一个最远距离的点 A,再做一次 dfs,找到的所有距离最远的点以及点 A 都是 deepest…

A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest root. Input Specification: E…

题目如下: A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest root. Input Specificat…

A graph which is connected and acyclic can be considered a tree. The hight of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest root. Input Specification: Ea…

A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest root. Input Specification: E…

Deepest Root A graph which is connected and acyclic can be considered a tree. The hight of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest root. Input Spec…

problem A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest root. Input Specific…

A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest root. Input Specification: E…

先并查集判断连通性,然后暴力每个点作为根节点判即可. #include<iostream> #include<cstring> #include<cmath> #include<algorithm> #include<cstdio> #include<queue> #include<vector> using namespace std; struct Edge { int a,b; }e[]; ],dep,U; ]; v…

dfs求最大层数并查集求连通个数 #include <iostream> #include <cstdio> #include <algorithm> #include <string.h> #include <string> #include <vector> using namespace std; /* dfs求最大层数 并查集求连通个数 */ +; int n; ; //最大层数 vector<int>deepro…

题意: 输入一个正整数N(N<=10000),然后输入N-1条边,求使得这棵树深度最大的根节点,递增序输出.如果不是一棵树,输出这张图有几个部分. trick: 时间比较充裕数据可能也不是很极限,所以用了一个暴力的手段.直接枚举度数为1的点进行深度优先搜索,如果递归了一万次还没有return就当它有环.(这道题的数据不存在只有一个带有自环的部分,即如有自环图必定不止一个)正解应当是dfs一次以后找到一些可能是最深根的叶子结点们,然后对这些叶子节点们依次dfs,再找到对应的一些叶子节点们.成对的叶…

[题目大意] 给出n个结点和n-1条边,问它们能否形成一棵n个结点的树,如果能,从中选出结点作为树根,使整棵树的高度最大.输出所有满足要求的可以作为树根的结点. [思路] 方法一:模拟. 1 连通.边数为n-1的图一定是一棵树.因此先判断连通图个数(用DFS遍历图,从而计算连通图个数),等于1则能形成一棵树. 2 遍历每一个节点,假设它为根节点构造一棵树. 方法二: 1 由于连通.边数为n-1的图一定是一棵树,因此需要判断给定数据是否能使图连通.2 确定图连通后,则确定了树,选择合适根结点使树高…

第一次出现超时 ac不了的题 思路一:对于每个节点用一次dfs dfs中 记录到当前的最长路径,若大于最长,则清除set,并加入当前节点 思路二:先查找只有一个相邻节点的节点进行dfs,由于可能存在闭环,对为访问的节点dfs 思路三:(TQL),大神思路,先以1节点为根用一次dfs(1),求出以1为根的最深点集合,并且完成深度搜索一次,可以知道是否还有不可达点, 如果还有没访问,继续遍历,可以的到连通分量数. 如果大于1,直接打印错误信息 否则,对最深点集合的其中一个进行dfs 即为答案. //…

这道题的关键在于如何求两个最远的结点,二叉树比较容易一直DFS就能找到,但是普通树就比较麻烦.要先找到一端,再去找另外一端,两端的并集就是答案.因为结点都是对称的,所以两端都是答案.还要注意去重,12 13这种就会重复. #include<bits/stdc++.h> using namespace std; ; vector<int>pre[maxn]; int n; bool vis[maxn]; vector<int>ans; void DFS(int s) {…

1021. Deepest Root (25) A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest root…

1021. Deepest Root (25) 时间限制 1500 ms 内存限制 65536 kB 代码长度限制 16000 B 判题程序 Standard 作者 CHEN, Yue A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root t…

Source: PAT A1021 Deepest Root (25 分) Description: A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root…

A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest root. Input Specification: E…

题目 A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest root. Input Specification…

A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest root. Input Specification: E…

PAT甲级1066. Root of AVL Tree 题意: 构造AVL树,返回root点val. 思路: 了解AVL树的基本性质. AVL树 ac代码: C++ // pat1066.cpp : 定义控制台应用程序的入口点. // #include "stdafx.h" #include<iostream> #include<cstdio> #include<string> #include<algorithm> #include&l…

A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest root. Input Specification: E…

1021 个位数统计 (15)(15 分) 给定一个k位整数N = d~k-1~*10^k-1^ + ... + d~1~*10^1^ + d~0~ (0<=d~i~<=9, i=0,...,k-1, d~k-1~>0),请编写程序统计每种不同的个位数字出现的次数.例如:给定N = 100311,则有2个0,3个1,和1个3. 输入格式: 每个输入包含1个测试用例,即一个不超过1000位的正整数N. 输出格式: 对N中每一种不同的个位数字,以D:M的格式在一行中输出该位数字D及其在N中出…