Breadth First Traversal

I/P:

7

8

0 1 10

1 2 10

2 3 10

0 3 10

3 4 10

4 5 10

5 6 10

4 6 10

2

O/P:

2@2

1@21

3@23

0@210

4@234

5@2345

6@2346

package pep.Day40;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Queue;

public class Breadth_First_Traversal {
    static class Edge {
        int src;
        int nbr;

        Edge(int src, int nbr) {
            this.src = src;
            this.nbr = nbr;
        }
    }

    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        int vtces = Integer.parseInt(br.readLine());
        ArrayList<Edge>[] graph = new ArrayList[vtces];
        for (int i = 0; i < vtces; i++) {
            graph[i] = new ArrayList<>();
        }

        int edges = Integer.parseInt(br.readLine());
        for (int i = 0; i < edges; i++) {
            String[] parts = br.readLine().split(" ");
            int v1 = Integer.parseInt(parts[0]);
            int v2 = Integer.parseInt(parts[1]);
            graph[v1].add(new Edge(v1, v2));
            graph[v2].add(new Edge(v2, v1));
        }

        int src = Integer.parseInt(br.readLine());

        method1(graph, vtces, src);

        method2(graph, vtces, src);
    }

    private static void method2(ArrayList<Edge>[] graph, int vtces, int src) {
        boolean[] visited = new boolean[vtces];
        Queue<Pair> queue = new ArrayDeque<>();
        queue.add(new Pair(src, src + ""));
        while (!queue.isEmpty()) {
            Pair out = queue.remove();
            if (!visited[out.vertice])
                System.out.println(out.vertice + "@" + out.psf);
            visited[out.vertice] = true;

            for (Edge e : graph[out.vertice]) {
                if (!visited[e.nbr]) {
                    queue.add(new Pair(e.nbr, out.psf + e.nbr));
                }
            }

        }
    }

    private static void method1(ArrayList<Edge>[] graph, int vtces, int src) {
        Queue<Pair> queue = new ArrayDeque<>();
        String path = "";
        queue.add(new Pair(src, path + src));
        boolean[] visited = new boolean[vtces];
        visited[src] = true;
        while (queue.size() > 0) {
            Pair top = queue.remove();
            for (Edge e : graph[top.vertice]) {
                if (!visited[e.nbr]) {
                    Pair child = new Pair(e.nbr, top.psf + e.nbr);
                    visited[e.nbr] = true;
                    queue.add(child);
                }
            }
            System.out.println(top.vertice + "@" + top.psf);
        }
    }

    static class Pair {
        int vertice;
        String psf;

        Pair(int dest, String path) {
            this.vertice = dest;
            this.psf = path;
        }
    }
}