Simple BFS Traversal using Java

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package main;

/**
 *
 * @author markjasongalang
 */

/**
 *
 *  Use this as input: (copy-paste in terminal)
 *  3
 *  4 2
 *  1 2
 *  2 3
 *  5 3
 *  1 2
 *  2 3
 *  1 3
 *  6 3
 *  1 2
 *  3 4
 *  5 6
 *
 */

import java.io.*;
import java.util.*;

public class Main {
    static LinkedList<Integer> a[];
    static boolean visited[];

    static void BFS(int u) {
        LinkedList<Integer> q = new LinkedList<Integer>();
        visited[u] = true;
        q.add(u);
        while ((int) q.size() != 0) {
            u = q.poll();
            ListIterator it = a[u].listIterator();
            while (it.hasNext()) {
                int v = (int) it.next();
                if (!visited[v]) {
                    visited[v] = true;
                    System.out.print(" -> " + (v + 1));
                    q.add(v);
                }
            }
        }
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int tt = in.nextInt();
        for (int qq = 1; qq <= tt; qq++) {
            int n = in.nextInt();
            int m = in.nextInt();
            a = new LinkedList[n];
            for (int i = 0; i < n; i++) {
                a[i] = new LinkedList();
            }
            for (int i = 0; i < m; i++) {
                int u = in.nextInt();
                int v = in.nextInt();
                --u; --v;
                a[u].add(v);
                a[v].add(u);
            }
            visited = new boolean[n];
            Arrays.fill(visited, false);
            for (int u = 0; u < n; u++) {
                if (!visited[u]) {
                    System.out.print(u + 1);
                    BFS(u);
                    System.out.println();
                }
            }
            System.out.println("");
        }
    }
}