結果

問題 No.898 tri-βutree
コンテスト
ユーザー hiromi_ayase
提出日時 2019-10-05 01:21:52
言語 Java
(openjdk 23)
結果
WA  
実行時間 -
コード長 5,433 bytes
コンパイル時間 3,462 ms
コンパイル使用メモリ 90,472 KB
実行使用メモリ 59,576 KB
最終ジャッジ日時 2024-10-04 04:10:36
合計ジャッジ時間 11,003 ms
ジャッジサーバーID
（参考情報） 		judge1 / 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
sample AC * 1
other AC * 1 WA * 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.Arrays;

public class Main {

  private static void solve() {
    int n = ni();
    int[] from = new int[n - 1];
    int[] to = new int[n - 1];
    int[] w = new int[n - 1];
    for (int i = 0; i < n - 1; i++) {
      from[i] = ni();
      to[i] = ni();
      w[i] = ni();
    }
    long[] wdep = new long[n];
    int[][][] g = packWD(n, from, to, w);
    int[][] p3 = parents3(g, 0, wdep);
    int[] dep = p3[2];
    int[] par = p3[0];

    int[][] spar = logstepParents(par);

    int q = ni();
    for (int i = 0; i < q; i++) {
      int x = ni();
      int y = ni();
      int z = ni();

      int anc1 = lca2(x, y, spar, dep);
      int anc2 = lca2(y, z, spar, dep);
      int anc3 = lca2(z, x, spar, dep);
      long ret = wdep[x] + wdep[y] + wdep[z] - wdep[anc1] - wdep[anc2] - wdep[anc3];
      out.println(ret);
    }
  }

  public static int lca2(int a, int b, int[][] spar, int[] depth) {
    if (depth[a] < depth[b]) {
      b = ancestor(b, depth[b] - depth[a], spar);
    } else if (depth[a] > depth[b]) {
      a = ancestor(a, depth[a] - depth[b], spar);
    }

    if (a == b)
      return a;
    int sa = a, sb = b;
    for (int low = 0, high = depth[a], t = Integer.highestOneBit(high), k =
        Integer.numberOfTrailingZeros(t); t > 0; t >>>= 1, k--) {
      if ((low ^ high) >= t) {
        if (spar[k][sa] != spar[k][sb]) {
          low |= t;
          sa = spar[k][sa];
          sb = spar[k][sb];
        } else {
          high = low | t - 1;
        }
      }
    }
    return spar[0][sa];
  }

  protected static int ancestor(int a, int m, int[][] spar) {
    for (int i = 0; m > 0 && a != -1; m >>>= 1, i++) {
      if ((m & 1) == 1)
        a = spar[i][a];
    }
    return a;
  }

  public static int[][] logstepParents(int[] par) {
    int n = par.length;
    int m = Integer.numberOfTrailingZeros(Integer.highestOneBit(n - 1)) + 1;
    int[][] pars = new int[m][n];
    pars[0] = par;
    for (int j = 1; j < m; j++) {
      for (int i = 0; i < n; i++) {
        pars[j][i] = pars[j - 1][i] == -1 ? -1 : pars[j - 1][pars[j - 1][i]];
      }
    }
    return pars;
  }


  public static int[][] parents3(int[][][] g, int root, long[] wdepth) {
    int n = g.length;
    int[] par = new int[n];
    Arrays.fill(par, -1);

    int[] dep = new int[n];

    int[] q = new int[n];
    q[0] = root;
    for (int p = 0, r = 1; p < r; p++) {
      int cur = q[p];
      for (int[] e : g[cur]) {
        int nex = e[0];
        if (par[cur] != nex) {
          q[r++] = nex;
          par[nex] = cur;
          wdepth[nex] = wdepth[cur] + e[1];
          dep[nex] = dep[cur] + 1;
        }
      }
    }
    return new int[][] {par, q, dep};
  }

  public static int[][][] packWD(int n, int[] from, int[] to, int[] w) {
    int[][][] g = new int[n][][];
    int[] p = new int[n];
    for (int f : from)
      p[f]++;
    for (int i = 0; i < n; i++)
      g[i] = new int[p[i]][2];
    for (int i = 0; i < from.length; i++) {
      --p[from[i]];
      g[from[i]][p[from[i]]][0] = to[i];
      g[from[i]][p[from[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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