백준 1260

package baekjoon.DFS와BFS;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedList;
import java.util.Queue;
import java.util.StringTokenizer;

class Main1260 {

   static StringBuilder sb = new StringBuilder();
   static int N, M, V;
   static ArrayList<Integer>[] graph;
   static Queue<Integer> q;
   static boolean[] visited;

   public static void main(String[] args) throws Exception {
      input();
      go();
      System.out.println(sb);
   }

   private static void go() {
      dfs(V);
      sb.append('\n');
      init();
      bfs(V);
   }

   private static void init() {
      for (int i = 1; i <= N; i++) {
         visited[i] = false;
      }
   }

   private static void dfs(int start) {
      visited[start] = true;
      sb.append(start).append(' ');

      for (Integer a : graph[start]) {
         if (visited[a])
            continue;
         dfs(a);
      }
   }

   private static void bfs(int start) {
      Queue<Integer> q = new LinkedList<>();

      q.add(start);
      visited[start] = true;

      while (!q.isEmpty()) {
         Integer a = q.poll();
         sb.append(a).append(' ');

         for (Integer b : graph[a]) {
            if (visited[b])
               continue;
            q.add(b);
            visited[b] = true;
         }
      }
   }

   private static void input() throws IOException {
      BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      StringTokenizer st = new StringTokenizer(br.readLine());
      N = Integer.parseInt(st.nextToken());
      M = Integer.parseInt(st.nextToken());
      V = Integer.parseInt(st.nextToken());
      graph = new ArrayList[N + 1];
      visited = new boolean[N + 1];
      for (int i = 1; i <= N; i++) {
         graph[i] = new ArrayList<>();
      }
      for (int i = 0; i < M; i++) {
         st = new StringTokenizer(br.readLine());
         int a = Integer.parseInt(st.nextToken());
         int b = Integer.parseInt(st.nextToken());
         graph[a].add(b);
         graph[b].add(a);
      }
      for (int i = 1; i <= N; i++) {
         Collections.sort(graph[i]);
      }
   }
}