結果

問題 No.768 Tapris and Noel play the game on Treeone
コンテスト
ユーザー hiromi_ayase
提出日時 2018-12-19 12:39:01
言語 Java
(openjdk 23)
結果
WA  
(最新)
AC  
(最初)
実行時間 -
コード長 4,631 bytes
コンパイル時間 2,966 ms
コンパイル使用メモリ 90,744 KB
実行使用メモリ 73,776 KB
最終ジャッジ日時 2024-09-25 07:57:01
合計ジャッジ時間 14,009 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge4
このコードへのチャレンジ
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ファイルパターン 結果
sample WA * 2
other WA * 22
権限があれば一括ダウンロードができます

ソースコード

diff # 

import java.util.HashSet;
import java.util.Set;

public class Main {
  private static void solve() {
    int n = ni();
    int[] from = new int[n - 1];
    int[] to = new int[n - 1];
    for (int i = 0; i < n - 1; i++) {
      from[i] = ni() - 1;
      to[i] = ni() - 1;
    }
    int[][][] g = packWU(n, from, to, new int[n-1]);
    boolean[] ret = new boolean[n];
    dfs1(0, -1, g);
    dfs2(0, -1, false, g, ret);
    
    StringBuilder sb = new StringBuilder();
    int cnt = 0;
    for (int i = 0; i < n ; i++) {
      if (!ret[i]) {
        sb.append(i + 1 + "\n");
        cnt ++;
      }
    }
    System.out.println(cnt);
    System.out.println(sb);
  }

  private static void dfs2(int now, int pre, boolean dpar, int[][][] g, boolean[] ret) {
    Set<Integer> win = new HashSet<>();
    for (int[] v : g[now]) {
      int next = v[0];
      if (next == pre) {
        if (dpar) {
          win.add(next);
          ret[now] = true;
        }
      } else {
        if (v[1] == 1) {
          win.add(next);
          ret[now] = true;
        }
      }
    }

    for (int[] v : g[now]) {
      int next = v[0];
      if (next == pre) {
        continue;
      }
      boolean ndpar = win.size() == 0 || win.size() == 1 && win.contains(next);
      dfs2(next, now, ndpar, g, ret);
    }
  }

  private static boolean dfs1(int now, int pre, int[][][] g) {
    boolean ret = false;
    for (int[] v : g[now]) {
      int next = v[0];
      if (next == pre) {
        continue;
      }
      boolean x = !dfs1(next, now, g);
      v[1] = x ? 1 : 2;
      ret |= x;
    }
    return ret;
  }

  public static int[][][] packWU(int n, int[] from, int[] to, int[] w) {
    return packWU(n, from, to, w, from.length);
  }

  public static int[][][] packWU(int n, int[] from, int[] to, int[] w, int sup) {
    int[][][] g = new int[n][][];
    int[] p = new int[n];
    for (int i = 0; i < sup; i++)
      p[from[i]]++;
    for (int i = 0; i < sup; i++)
      p[to[i]]++;
    for (int i = 0; i < n; i++)
      g[i] = new int[p[i]][2];
    for (int i = 0; i < sup; i++) {
      --p[from[i]];
      g[from[i]][p[from[i]]][0] = to[i];
      g[from[i]][p[from[i]]][1] = w[i];
      --p[to[i]];
      g[to[i]][p[to[i]]][0] = from[i];
      g[to[i]][p[to[i]]][1] = w[i];
    }
    return g;
  }

  public static void main(String[] args) {
    new Thread(null, new Runnable() {
      @Override
      public void run() {
        long start = System.currentTimeMillis();
        String debug = args.length > 0 ? args[0] : null;
        if (debug != null) {
          try {
            is = java.nio.file.Files.newInputStream(java.nio.file.Paths.get(debug));
          } catch (Exception e) {
            throw new RuntimeException(e);
          }
        }
        reader = new java.io.BufferedReader(new java.io.InputStreamReader(is), 32768);
        solve();
        out.flush();
        tr((System.currentTimeMillis() - start) + "ms");
      }
    }, "", 64000000).start();
  }

  private static java.io.InputStream is = System.in;
  private static java.io.PrintWriter out = new java.io.PrintWriter(System.out);
  private static java.util.StringTokenizer tokenizer = null;
  private static java.io.BufferedReader reader;

  public static String next() {
    while (tokenizer == null || !tokenizer.hasMoreTokens()) {
      try {
        tokenizer = new java.util.StringTokenizer(reader.readLine());
      } catch (Exception e) {
        throw new RuntimeException(e);
      }
    }
    return tokenizer.nextToken();
  }

  private static double nd() {
    return Double.parseDouble(next());
  }

  private static long nl() {
    return Long.parseLong(next());
  }

  private static int[] na(int n) {
    int[] a = new int[n];
    for (int i = 0; i < n; i++)
      a[i] = ni();
    return a;
  }

  private static char[] ns() {
    return next().toCharArray();
  }

  private static long[] nal(int n) {
    long[] a = new long[n];
    for (int i = 0; i < n; i++)
      a[i] = nl();
    return a;
  }

  private static int[][] ntable(int n, int m) {
    int[][] table = new int[n][m];
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        table[i][j] = ni();
      }
    }
    return table;
  }

  private static int[][] nlist(int n, int m) {
    int[][] table = new int[m][n];
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        table[j][i] = ni();
      }
    }
    return table;
  }

  private static int ni() {
    return Integer.parseInt(next());
  }

  private static void tr(Object... o) {
    if (is != System.in)
      System.out.println(java.util.Arrays.deepToString(o));
  }
}
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