結果

問題 No.843 Triple Primes
ユーザー amotoma3amotoma3
提出日時 2019-07-06 10:51:09
言語 Java21
(openjdk 21)
結果
AC  
実行時間 130 ms / 2,000 ms
コード長 4,407 bytes
コンパイル時間 3,775 ms
コンパイル使用メモリ 78,940 KB
実行使用メモリ 58,400 KB
最終ジャッジ日時 2023-10-19 17:59:36
合計ジャッジ時間 9,485 ms
ジャッジサーバーID
（参考情報） 		judge14 / 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 54 ms
53,568 KB
testcase_01 AC 127 ms
57,508 KB
testcase_02 AC 59 ms
53,592 KB
testcase_03 AC 58 ms
53,592 KB
testcase_04 AC 61 ms
53,596 KB
testcase_05 AC 57 ms
53,592 KB
testcase_06 AC 61 ms
52,972 KB
testcase_07 AC 123 ms
58,256 KB
testcase_08 AC 127 ms
58,064 KB
testcase_09 AC 117 ms
58,300 KB
testcase_10 AC 124 ms
58,400 KB
testcase_11 AC 126 ms
58,292 KB
testcase_12 AC 116 ms
58,084 KB
testcase_13 AC 122 ms
58,296 KB
testcase_14 AC 126 ms
58,188 KB
testcase_15 AC 117 ms
58,116 KB
testcase_16 AC 123 ms
58,072 KB
testcase_17 AC 54 ms
53,572 KB
testcase_18 AC 54 ms
53,580 KB
testcase_19 AC 54 ms
53,584 KB
testcase_20 AC 100 ms
56,160 KB
testcase_21 AC 86 ms
55,520 KB
testcase_22 AC 108 ms
58,256 KB
testcase_23 AC 116 ms
58,388 KB
testcase_24 AC 95 ms
55,984 KB
testcase_25 AC 96 ms
56,476 KB
testcase_26 AC 127 ms
58,396 KB
testcase_27 AC 88 ms
55,444 KB
testcase_28 AC 118 ms
58,140 KB
testcase_29 AC 116 ms
55,968 KB
testcase_30 AC 130 ms
58,036 KB
testcase_31 AC 91 ms
55,248 KB
testcase_32 AC 90 ms
55,108 KB
testcase_33 AC 113 ms
55,976 KB
testcase_34 AC 115 ms
58,008 KB
testcase_35 AC 130 ms
58,160 KB
testcase_36 AC 97 ms
56,092 KB
testcase_37 AC 125 ms
58,036 KB
testcase_38 AC 125 ms
58,032 KB
testcase_39 AC 129 ms
58,336 KB
testcase_40 AC 56 ms
53,580 KB
testcase_41 AC 54 ms
53,576 KB
testcase_42 AC 128 ms
58,196 KB
testcase_43 AC 119 ms
58,088 KB
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ソースコード

diff # 

import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.BufferedWriter;
import java.io.Writer;
import java.util.Set;
import java.io.OutputStreamWriter;
import java.util.InputMismatchException;
import java.io.IOException;
import java.util.TreeSet;
import java.io.InputStream;
import java.util.ArrayList;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        No843 solver = new No843();
        solver.solve(1, in, out);
        out.close();
    }

    static class No843 {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            int n = in.readInt();
            Set<Integer> primes = new TreeSet<>(new Prime(n).getPrimes());

            int ans = 0;
            for (int prime : primes) {
                if (prime * prime > n + 2) break;
                if (primes.contains(prime * prime - 2)) ans++;
            }
            out.printLine(n == 1 ? 0 : 2 * ans - 1);
        }

    }

    static class Prime {
        private int n;
        private boolean[] isPrime;
        private ArrayList<Integer> primes;

        public Prime(int n) {
            this.n = n;
            isPrime = new boolean[n + 1];
            primes = new ArrayList<>();
            sieve();
        }

        private void sieve() {
            for (int i = 2; i <= n; i++) {
                if (!isPrime[i]) {
                    primes.add(i);
                    for (long j = (long) i * i; j <= n; j += i) {
                        isPrime[(int) j] = true;
                    }
                }
            }
        }

        public ArrayList<Integer> getPrimes() {
            return primes;
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public int readInt() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void close() {
            writer.close();
        }

        public void printLine(int i) {
            writer.println(i);
        }

    }
}
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