24_BFS.java

import java.util.*;

public class BFS {
    private int vertices;
    private LinkedList<Integer>[] adjList;

    BFS(int v) {
        vertices = v;
        adjList = new LinkedList[v];
        for (int i = 0; i < v; i++)
            adjList[i] = new LinkedList<>();
    }

    void addEdge(int src, int dest) {
        adjList[src].add(dest);
    }

    void bfs(int start) {
        boolean[] visited = new boolean[vertices];
        Queue<Integer> queue = new LinkedList<>();
        visited[start] = true;
        queue.add(start);
        System.out.print("BFS Traversal: ");
        while (!queue.isEmpty()) {
            int node = queue.poll();
            System.out.print(node + " ");
            for (int adj : adjList[node]) {
                if (!visited[adj]) {
                    visited[adj] = true;
                    queue.add(adj);
                }
            }
        }
    }

    public static void main(String[] args) {
        BFS graph = new BFS(5);
        graph.addEdge(0, 1);
        graph.addEdge(0, 2);
        graph.addEdge(1, 3);
        graph.addEdge(1, 4);
        System.out.println("Graph BFS starting from node 0:");
        graph.bfs(0);
    }
}