使用DFS检查无向图是否连通的Java程序

给定一个无向图，任务是检查给定的图是否使用 DFS 连接。

连通图是在拓扑空间意义上连通的图，即从图中的任何节点到任何其他节点总是有一条路径。未连接的图称为断开连接。

例子：

Input:

Output: Graph is connected

Input:

Output: Graph is disconnected

方法：

1. 取一个布尔访问 [] 数组。
2. 从任何顶点开始 DFS（深度优先搜索），并将访问过的顶点标记为 True 在visited[] 数组中。
3. DFS 完成后，检查是否所有访问过的 [] 数组中的顶点都标记为 True。
4. 如果是，则图形已连接，否则图形未连接或断开连接。

代码：

Java

// Java Program to check if 
// an undirected graph is connected or not
// using DFS
  
import java.util.*; 
  
public class checkConnectivity {
      
    // Graph class
    static class Graph{
          
        int vertices;
        // Linked list for adjacency list of a vertex
        LinkedList adjacencyList [];
  
        @SuppressWarnings("unchecked")
        public Graph(int vertices)
        {
            this.vertices = vertices;
            adjacencyList = new LinkedList[vertices];
            
            for (int i = 0; i();
            }
        }
          
        // Function for adding edges
        public void addEdge(int source, int dest)
        {
            adjacencyList.addFirst(dest);
            adjacencyList[dest].addFirst(source);
        }
    }
  
    // Function to check if the graph is connected or not
    public void isConnected(Graph graph){
  
        int vertices = graph.vertices;
        LinkedList adjacencyList [] = graph.adjacencyList;
  
        // Take a boolean visited array
        boolean[] visited = new boolean[vertices];
  
        // Start the DFS from vertex 0
        DFS(0, adjacencyList, visited);
  
        // Check if all the vertices are visited
        // Set connected to False if one node is unvisited
        boolean connected = true;
        
        for (int i = 0; i  adjacencyList [], boolean[] visited){
  
        // Mark the vertex visited as True
        visited = true;
  
        // Travel the adjacent neighbours
        for (int i = 0; i 

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输出

Graph 1:- Graph is connected
Graph 2:- Graph is disconnected