結果

問題 No.843 Triple Primes
ユーザー hiromi_ayasehiromi_ayase
提出日時 2019-06-28 21:44:10
言語 Java21
(openjdk 21)
結果
AC  
実行時間 330 ms / 2,000 ms
コード長 4,445 bytes
コンパイル時間 4,135 ms
コンパイル使用メモリ 91,152 KB
実行使用メモリ 61,000 KB
最終ジャッジ日時 2023-10-19 17:40:24
合計ジャッジ時間 15,023 ms
ジャッジサーバーID
（参考情報） 		judge15 / judge13
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 79 ms
54,444 KB
testcase_01 AC 330 ms
61,000 KB
testcase_02 AC 91 ms
54,444 KB
testcase_03 AC 95 ms
55,096 KB
testcase_04 AC 95 ms
55,076 KB
testcase_05 AC 96 ms
54,984 KB
testcase_06 AC 97 ms
54,692 KB
testcase_07 AC 282 ms
58,948 KB
testcase_08 AC 303 ms
60,904 KB
testcase_09 AC 327 ms
60,744 KB
testcase_10 AC 278 ms
60,748 KB
testcase_11 AC 307 ms
60,972 KB
testcase_12 AC 323 ms
60,652 KB
testcase_13 AC 315 ms
60,792 KB
testcase_14 AC 319 ms
60,876 KB
testcase_15 AC 280 ms
60,844 KB
testcase_16 AC 283 ms
60,884 KB
testcase_17 AC 80 ms
54,456 KB
testcase_18 AC 80 ms
54,440 KB
testcase_19 AC 81 ms
54,448 KB
testcase_20 AC 167 ms
58,696 KB
testcase_21 AC 142 ms
58,712 KB
testcase_22 AC 224 ms
56,720 KB
testcase_23 AC 220 ms
58,532 KB
testcase_24 AC 162 ms
58,664 KB
testcase_25 AC 158 ms
58,636 KB
testcase_26 AC 327 ms
60,752 KB
testcase_27 AC 113 ms
57,696 KB
testcase_28 AC 316 ms
60,976 KB
testcase_29 AC 170 ms
58,552 KB
testcase_30 AC 321 ms
60,756 KB
testcase_31 AC 125 ms
58,140 KB
testcase_32 AC 112 ms
57,772 KB
testcase_33 AC 180 ms
58,504 KB
testcase_34 AC 217 ms
58,688 KB
testcase_35 AC 329 ms
60,832 KB
testcase_36 AC 151 ms
58,660 KB
testcase_37 AC 268 ms
60,748 KB
testcase_38 AC 235 ms
60,752 KB
testcase_39 AC 326 ms
60,984 KB
testcase_40 AC 79 ms
54,568 KB
testcase_41 AC 79 ms
54,444 KB
testcase_42 AC 286 ms
60,852 KB
testcase_43 AC 317 ms
60,656 KB
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ソースコード

diff # 

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

public class Main {


  private static void solve() {
    int n = ni();

    int[] primes = sieveEratosthenes(n);
    Set<Integer> sq = new HashSet<>();
    for (int p : primes) {
      sq.add(p);
    }

    int m = primes.length;
    int ret = 0;
    for (int i = 0; i < m; i ++) {
      for (int j = 0; j < m && primes[j] * primes[j] <= n * 2; j ++) {
        if (sq.contains(primes[j] * primes[j] - primes[i])) {
          ret ++;
        }
      }
    }
    System.out.println(ret);
  }

  public static int[] sieveEratosthenes(int n) {
    if (n <= 32) {
      int[] primes = {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31};
      for (int i = 0; i < primes.length; i++) {
        if (n < primes[i]) {
          return Arrays.copyOf(primes, i);
        }
      }
      return primes;
    }

    int u = n + 32;
    double lu = Math.log(u);
    int[] ret = new int[(int) (u / lu + u / lu / lu * 1.5)];
    ret[0] = 2;
    int pos = 1;

    int[] isnp = new int[(n + 1) / 32 / 2 + 1];
    int sup = (n + 1) / 32 / 2 + 1;

    int[] tprimes = {3, 5, 7, 11, 13, 17, 19, 23, 29, 31};
    for (int tp : tprimes) {
      ret[pos++] = tp;
      int[] ptn = new int[tp];
      for (int i = (tp - 3) / 2; i < tp << 5; i += tp)
        ptn[i >> 5] |= 1 << (i & 31);
      for (int j = 0; j < sup; j += tp) {
        for (int i = 0; i < tp && i + j < sup; i++) {
          isnp[j + i] |= ptn[i];
        }
      }
    }

    // 3,5,7
    // 2x+3=n
    int[] magic = {0, 1, 23, 2, 29, 24, 19, 3, 30, 27, 25, 11, 20, 8, 4, 13, 31, 22, 28, 18, 26, 10,
        7, 12, 21, 17, 9, 6, 16, 5, 15, 14};
    int h = n / 2;
    for (int i = 0; i < sup; i++) {
      for (int j = ~isnp[i]; j != 0; j &= j - 1) {
        int pp = i << 5 | magic[(j & -j) * 0x076be629 >>> 27];
        int p = 2 * pp + 3;
        if (p > n)
          break;
        ret[pos++] = p;
        if ((long) p * p > n)
          continue;
        for (int q = (p * p - 3) / 2; q <= h; q += p)
          isnp[q >> 5] |= 1 << q;
      }
    }

    return Arrays.copyOf(ret, pos);
  }

  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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