백준 11725

package baekjoon.트리;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.StringTokenizer;

class Main11725 {

   static int N;
   static ArrayList<Integer>[] g;
   static int[] parent;
   static StringBuilder sb = new StringBuilder();

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

   private static void go() {
      dfs(1, -1);
      for (int i = 2; i <= N; i++) {
         sb.append(parent[i]).append('\n');
      }
   }

   private static void dfs(int x, int par) {
      for (Integer y : g[x]) {
         if (y == par)
            continue;
         parent[y] = x;
         dfs(y, x);
      }
   }

   private static void input() throws IOException {
      BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      StringTokenizer st;
      N = Integer.parseInt(br.readLine());
      g = new ArrayList[N + 1];
      parent = new int[N + 1];
      for (int i = 1; i <= N; i++) {
         g[i] = new ArrayList<>();
      }
      for (int i = 1; i < N; i++) {
         st = new StringTokenizer(br.readLine());
         int a = Integer.parseInt(st.nextToken());
         int b = Integer.parseInt(st.nextToken());
         g[a].add(b);
         g[b].add(a);
      }
   }
}