题目介绍: 输入一个简单无向图,求出图中连通块的数目. Input 输入的第一行包含两个整数n和m,n是图的顶点数,m是边数.1<=n<=1000,0<=m<=10000. 以下m行,每行是一个数对v y,表示存在边(v,y).顶点编号从1开始. Output 单独一行输出连通块的数目. Sample Input 5 3 1 2 1 3 2 4 Sample Output 2 思路: 利用广度搜索,计算广度搜索的次数即为结果. 具体代码如下: #include <iostre…

题目描述: 输入一个简单无向图,求出图中连通块的数目 输入: 输入的第一行包含两个整数n和m,n是图的顶点数,m是边数.1<=n<=1000,0<=m<=10000. 以下m行,每行是一个数对v y,表示存在边(v,y).顶点编号从1开始. 题目分析: 利用深度优先搜索寻找连通块数,一趟深度优先搜索为一个连通块,深度优先搜索次数为块数. #include<iostream> #include<memory> using namespace std; cons…

题意:求图中的连通块数,注意孤立的算自连通! 例如:6个顶点3条路径,其中路径为:1->2    4->5  1->3 那么有(1-2&&1->3) + (4->5) + (6) 共3个连通块! 解法:对每个节点宽搜! #include<iostream> #include<memory.h> #include<queue> using namespace std; ][]; ]; int N,M; int main(){…

Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to find the number of connected components in an undirected graph. Example 1: 0          3 |          | 1 --- 2    4 Given n = 5 and…

原题链接在这里:https://leetcode.com/problems/number-of-connected-components-in-an-undirected-graph/ 题目: Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to find the number of connected com…

Number of Connected Components in an Undirected Graph Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to find the number of connected components in an undirected graph. Example 1:…

Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to find the number of connected components in an undirected graph. Example 1: 0          3 |          | 1 --- 2    4 Given n = 5 and…

［抄题］: Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to find the number of connected components in an undirected graph. Example 1: Input: n = 5 and edges = [[0, 1], [1, 2], [3, 4]…

原题链接在这里:https://leetcode.com/problems/number-of-connected-components-in-an-undirected-graph/ 题目: Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to find the number of connected com…

Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to find the number of connected components in an undirected graph. Example 1: Input: n = 5 and edges = [[0, 1], [1, 2], [3, 4]] 0 3…

Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to find the number of connected components in an undirected graph. Example 1: | | --- Given n = 5 and edges = [[0, 1], [1, 2], [3, 4…

Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to find the number of connected components in an undirected graph. Example 1: 0        3 |          | 1 --- 2    4 Given n = 5 and e…

作者: 负雪明烛 id: fuxuemingzhu 个人博客:http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 并查集 日期 题目地址:https://leetcode-cn.com/problems/number-of-connected-components-in-an-undirected-graph/ 题目描述 Given n nodes labeled from 0 to n - 1 and a list of undirected edges (ea…

310. Minimum Height Trees queue:  degree为1的顶点 degree[ i ] : 和 i 顶点关联的边数. 先添加整个图,然后BFS删除每一层degree为1的节点. class Solution { public List<Integer> findMinHeightTrees(int n, int[][] edges) { List<Integer> result = new ArrayList<>(); if(n == 1){…

Description Find connected component in undirected graph. Each node in the graph contains a label and a list of its neighbors. (A connected component of an undirected graph is a subgraph in which any two vertices are connected to each other by paths,…

Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to check whether these edges make up a valid tree. For example: Given n = 5 and edges = [[0, 1], [0, 2], [0, 3], [1, 4]], return tru…

题目: 找出无向图汇总的相连要素 请找出无向图中相连要素的个数. 图中的每个节点包含其邻居的 1 个标签和 1 个列表.(一个无向图的相连节点(或节点)是一个子图,其中任意两个顶点通过路径相连,且不与超级图中的其它顶点相连.) 样例 给定图: A------B C \ | | \ | | \ | | \ | | D E 返回 {A,B,D}, {C,E}.其中有 2 个相连的元素,即{A,B,D}, {C,E} 解题: 广度优先+递归,写不出来,程序来源 Java程序: /** * Defini…

一 深度优先遍历,参考前面DFS(white and gray and black) 二 根据定点以及边数目进行判断 如果m(edge)大于n(vertex),那么肯定存在环 算法如下: 1 删除所有入度小于等于1的顶点, 并且将和这些顶点相关的顶点入度减1 2 将入度变为1的顶点全部删除,重复上述动作,如果最后还有顶点那么图中存在环 具体代码如下: #include <iostream> using namespace std; #define MAX_VERTEX_NUM 128 enum…

Find the Connected Component in the Undirected Graph Find the number connected component in the undirected graph. Each node in the graph contains a label and a list of its neighbors. (a connected component (or just component) of an undirected graph i…

Make a deep copy of an undirected graph, there could be cycles in the original graph. Assumptions The given graph is not null DFS /* * class GraphNode { * public int key; * public List<GraphNode> neighbors; * public GraphNode(int key) { * this.key =…

算连接的..那就是union find了 public class Solution { public int countComponents(int n, int[][] edges) { if(edges.length == 0) return n; int[] nodes = new int[n]; for(int i = 0; i < n;i++) nodes[i] = i; for(int i = 0; i < edges.length;i++) { int a = search(n…

Regular Union-Find practice one. #include <cmath> #include <cstdio> #include <climits> #include <vector> #include <iostream> #include <fstream> #include <algorithm> #include <unordered_set> #include <unor…

题目介绍: 输入一个无向图,指定一个顶点s开始bfs遍历,求出s到图中每个点的最短距离. 如果不存在s到t的路径,则记s到t的距离为-1.   Input 输入的第一行包含两个整数n和m,n是图的顶点数,m是边数.1<=n<=1000,0<=m<=10000. 以下m行,每行是一个数对v y,表示存在边(v,y).顶点编号从1开始.    Output 记s=1,在一行中依次输出:顶点1到s的最短距离,顶点2到s的最短距离,...,顶点n到s的最短距离. 每项输出之后加一个空格,包…

题意 给定一棵 \(n\) 个节点, \(m\) 条边的无向图,每个点有点权,有 \(q\) 个询问,每次询问若删去存在一个节点权值在 \([L,R]\) 范围外的边,剩下的图构成了多少个连通块(询问间相互独立). \(1\leq n,q \leq 10^5\) \(1\leq m \leq 2\times 10^5\) 思路 题目意思在简化一下,就是求连接两个点权在 \([L,R]\) 中的边和原图中的所有节点构成的连通块数. 对于两维的询问,在没有强制在线的情况下,可以考虑离线消维.我们把询…

Codeforces Round #485 (Div. 2) F. AND Graph 题目连接: http://codeforces.com/contest/987/problem/F Description You are given a set of size $m$ with integer elements between $0$ and $2^{n}-1$ inclusive. Let's build an undirected graph on these integers in…

E. Cyclic Components time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given an undirected graph consisting of nn vertices and mm edges. Your task is to find the number of connected…

You are given an undirected graph consisting of nn vertices and mm edges. Your task is to find the number of connected components which are cycles. Here are some definitions of graph theory. An undirected graph consists of two sets: set of nodes (cal…

Cyclic Components CodeForces - 977E You are given an undirected graph consisting of nn vertices and mm edges. Your task is to find the number of connected components which are cycles. Here are some definitions of graph theory. An undirected graph con…

E. Cyclic Components time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given an undirected graph consisting of nn vertices and mm edges. Your task is to find the number of connected…

不难想到,x有边连出的一定是 (2^n-1) ^ x 的一个子集,直接连子集复杂度是爆炸的...但是我们可以一个1一个1的消去,最后变成补集的一个子集. 但是必须当且仅当 至少有一个 a 等于 x 的时候, 可以直接dfs(all ^ x) ,否则直接消1连边... Discription You are given a set of size mm with integer elements between 00 and 2n−12n−1 inclusive. Let's build an u…