BOJ 1260 DFS BFS

import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;

public class Main {

    static ArrayList<Integer>[] adj;
    static boolean[] visited;

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int M = sc.nextInt();
        int start = sc.nextInt();

        adj = (ArrayList<Integer>[]) new ArrayList[N+1];
        for(int i=1; i<=N ;i++){
            adj[i] = new ArrayList<Integer>();
        }

        //input adj
        for(int i=0; i<M; i++){
            int u = sc.nextInt();
            int v = sc.nextInt();
            adj[u].add(v);
            adj[v].add(u);
        }

        for(int i=1; i<=N; i++){
            Collections.sort(adj[i]);
        }

        visited = new boolean[N+1];
        dfs(start);

        System.out.println();
        visited = new boolean[N+1];
        bfs(start);

    }

    private static void dfs(int x) {
        if(visited[x]) return;
        visited[x] = true;
        System.out.print(x + " ");
        for(int y : adj[x]){
            if(!visited[y])
                dfs(y);
        }
    }
    private static void bfs(int start){
        Queue<Integer> q = new LinkedList<>();
        q.add(start);
        visited[start] = true;
        while(!q.isEmpty()) {
            int x = q.remove();
            System.out.print(x + " ");
            for(int y : adj[x]){
                if(!visited[y]){
                    visited[y] = true;
                    q.add(y);
                }
            }
        }
    }
}

<Result>

4 5 1

1 2 

1 3

1 4

2 4

3 4

1 2 4 3 

1 2 3 4