結果

問題 No.763 Noelちゃんと木遊び
ユーザー hiromi_ayase
提出日時 2018-12-11 12:10:51
言語 Java
(openjdk 23)
結果
TLE  
実行時間 -
コード長 3,635 bytes
コンパイル時間 2,623 ms
コンパイル使用メモリ 92,248 KB
実行使用メモリ 66,072 KB
最終ジャッジ日時 2024-09-21 15:42:11
合計ジャッジ時間 10,083 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge3
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
other TLE * 1 -- * 20
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.PriorityQueue;

public class Main {
  private static void solve() {
    int n = ni();
    int[] from = new int[n - 1];
    int[] to = new int[n - 1];
    int[] cnt = new int[n];
    PriorityQueue<Integer> q = new PriorityQueue<>((o1, o2) -> {
      if (cnt[o1] == cnt[o2]) return o1 - o2;
      return cnt[o2] - cnt[o1];
    });

    for (int i = 0; i < n - 1; i ++) {
      from[i] = ni() - 1;
      to[i] = ni() - 1;
      cnt[from[i]] ++;
      cnt[to[i]] ++;
    }
    for (int i = 0; i < n; i ++) {
      q.add(i);
    }
    int[][] g = packU(n, from, to);
    
    int ret = 1;
    while (q.size() > 0 && cnt[q.peek()] >= 2) {
      int v = q.poll();

      ret += cnt[v] - 1;
      cnt[v] = -1;
      for (int u : g[v]) {
        if (cnt[u] >= 0) {
          q.remove(u);
          cnt[u] --;
          q.add(u);
        }
      }
    }
    System.out.println(ret);
  }

  static int[][] packU(int n, int[] from, int[] to) {
    int[][] g = new int[n][];
    int[] p = new int[n];
    for (int f : from)
        p[f]++;
    for (int t : to)
        p[t]++;
    for (int i = 0; i < n; i++)
        g[i] = new int[p[i]];
    for (int i = 0; i < from.length; i++) {
        g[from[i]][--p[from[i]]] = to[i];
        g[to[i]][--p[to[i]]] = from[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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