Breadth First Search (BFS) Program in Java

In this program, we are going to share Breadth First Search (BFS) Program in Java with the output. If you are a Java beginner and want to start learning the Java programming, then keep your close attention in this tutorial as I am going to share how to write a Java program for Breadth First Search (BFS).

Breadth First Search (BFS) Program in Java

Copy the below Java program and execute it with the help of Javac compiler. At the end of this program, We have shared the output of this program.

import java.io.*;

import java.util.*;
 
class BreadthFirstSearchProgram
{
    private int V;
    private LinkedList<Integer> adj[];
 
    //constructor
    BreadthFirstSearchProgram(int v)
    {
        V = v;
        adj = new LinkedList[v];
        for (int i=0; i<v; ++i)
            adj[i] = new LinkedList();
    }
 
    void addEdge(int v,int w)
    {
        adj[v].add(w);
    }
 
    void BFS(int s)
    {
        boolean visited[] = new boolean[V];
 
        LinkedList<Integer> queue = new LinkedList<Integer>();
 
        visited[s]=true;
        queue.add(s);
 
        while (queue.size() != 0)
        {
            s = queue.poll();
            System.out.print(s+" ");
 
            Iterator<Integer> i = adj[s].listIterator();

            while (i.hasNext())
            {
                int n = i.next();
                if (!visited[n])
                {
                    visited[n] = true;
                    queue.add(n);
                }
            }
        }
    }
 
    public static void main(String args[])
    {
        Graph g = new Graph(4);
 
        g.addEdge(0, 1);
        g.addEdge(0, 2);
        g.addEdge(1, 2);
        g.addEdge(2, 0);
        g.addEdge(2, 3);
        g.addEdge(3, 3);
 
        System.out.println("Following is Breadth First Traversal "+"(starting from node 2)");
 
        g.BFS(2);
    }
}

import java.io.*;

import java.util.*;

class BreadthFirstSearchProgram

{

private int V;

private LinkedList<Integer> adj[];

//constructor

BreadthFirstSearchProgram(int v)

{

V = v;

adj = new LinkedList[v];

for (int i=0; i<v; ++i)

adj[i] = new LinkedList();

}

void addEdge(int v,int w)

{

adj[v].add(w);

}

void BFS(int s)

{

boolean visited[] = new boolean[V];

LinkedList<Integer> queue = new LinkedList<Integer>();

visited[s]=true;

queue.add(s);

while (queue.size() != 0)

{

s = queue.poll();

System.out.print(s+" ");

Iterator<Integer> i = adj[s].listIterator();

while (i.hasNext())

{

int n = i.next();

if (!visited[n])

{

visited[n] = true;

queue.add(n);

}

public static void main(String args[])

{

Graph g = new Graph(4);

g.addEdge(0, 1);

g.addEdge(0, 2);

g.addEdge(1, 2);

g.addEdge(2, 0);

g.addEdge(2, 3);

g.addEdge(3, 3);

System.out.println("Following is Breadth First Traversal "+"(starting from node 2)");

g.BFS(2);

}

Following is Breadth First Traversal (starting from node 2)
2 0 3 1

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Breadth First Search (BFS) Program in Java

Breadth First Search (BFS) Program in Java

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