結果

問題 No.826 連絡網
ユーザー kusomushikusomushi
提出日時 2019-07-08 21:37:46
言語 Java21
(openjdk 21)
結果
AC  
実行時間 106 ms / 2,000 ms
コード長 4,905 bytes
コンパイル時間 2,323 ms
コンパイル使用メモリ 78,728 KB
実行使用メモリ 39,516 KB
最終ジャッジ日時 2024-05-03 05:23:09
合計ジャッジ時間 5,607 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge2
このコードへのチャレンジ
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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 55 ms
37,172 KB
testcase_01 AC 53 ms
37,044 KB
testcase_02 AC 53 ms
37,200 KB
testcase_03 AC 54 ms
37,308 KB
testcase_04 AC 55 ms
37,176 KB
testcase_05 AC 54 ms
37,184 KB
testcase_06 AC 53 ms
37,136 KB
testcase_07 AC 54 ms
37,176 KB
testcase_08 AC 52 ms
37,028 KB
testcase_09 AC 53 ms
37,324 KB
testcase_10 AC 54 ms
37,024 KB
testcase_11 AC 55 ms
37,376 KB
testcase_12 AC 86 ms
38,584 KB
testcase_13 AC 79 ms
38,280 KB
testcase_14 AC 83 ms
38,552 KB
testcase_15 AC 62 ms
37,404 KB
testcase_16 AC 78 ms
38,572 KB
testcase_17 AC 75 ms
38,212 KB
testcase_18 AC 83 ms
38,232 KB
testcase_19 AC 86 ms
39,432 KB
testcase_20 AC 87 ms
39,064 KB
testcase_21 AC 54 ms
37,532 KB
testcase_22 AC 75 ms
38,340 KB
testcase_23 AC 80 ms
38,456 KB
testcase_24 AC 80 ms
37,976 KB
testcase_25 AC 106 ms
39,440 KB
testcase_26 AC 81 ms
38,392 KB
testcase_27 AC 82 ms
39,016 KB
testcase_28 AC 81 ms
38,648 KB
testcase_29 AC 77 ms
38,192 KB
testcase_30 AC 102 ms
39,516 KB
testcase_31 AC 77 ms
38,096 KB
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ソースコード

diff # 

import java.io.*;
import java.util.*;

public class Main {

    static int N, P;

    public static void main(String[] args) {
        FastScanner sc = new FastScanner(System.in);
        N = sc.nextInt();
        P = sc.nextInt();

        System.out.println(solve());
    }

    static int solve() {
        if( P == 1 ) return 1;

        boolean[] sieve = new boolean[N+1];
        Arrays.fill(sieve, true);
        sieve[0] = false;
        sieve[1] = false;

        for (int i = 2; i <= N; i++) {
            if( sieve[i] ) {
                for (int d = 2; d*i <= N; d++) {
                    sieve[i*d] = false;
                }
            }
        }

        int cnt = 0;
        for (int i = 2; i <= N; i++) {
            if( i <= N/2 || !sieve[i] ) {
                cnt++;
            }
        }

        if( P > N/2 && sieve[P] ) {
            return 1;
        } else {
            return cnt;
        }
    }

    @SuppressWarnings("unused")
    static class FastScanner {
        private BufferedReader reader;
        private StringTokenizer tokenizer;

        FastScanner(InputStream in) {
            reader = new BufferedReader(new InputStreamReader(in));
            tokenizer = null;
        }

        String next() {
            if (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        String nextLine() {
            if (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    return reader.readLine();
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken("\n");
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        int[] nextIntArray(int n) {
            int[] a = new int[n];
            for (int i = 0; i < n; i++) a[i] = nextInt();
            return a;
        }

        int[] nextIntArray(int n, int delta) {
            int[] a = new int[n];
            for (int i = 0; i < n; i++) a[i] = nextInt() + delta;
            return a;
        }

        long[] nextLongArray(int n) {
            long[] a = new long[n];
            for (int i = 0; i < n; i++) a[i] = nextLong();
            return a;
        }
    }

    static void writeLines(int[] as) {
        PrintWriter pw = new PrintWriter(System.out);
        for (int a : as) pw.println(a);
        pw.flush();
    }

    static void writeLines(long[] as) {
        PrintWriter pw = new PrintWriter(System.out);
        for (long a : as) pw.println(a);
        pw.flush();
    }

    static void writeSingleLine(int[] as) {
        PrintWriter pw = new PrintWriter(System.out);
        for (int i = 0; i < as.length; i++) {
            if (i != 0) pw.print(" ");
            pw.print(as[i]);
        }
        pw.println();
        pw.flush();
    }

    static int max(int... as) {
        int max = Integer.MIN_VALUE;
        for (int a : as) max = Math.max(a, max);
        return max;
    }

    static int min(int... as) {
        int min = Integer.MAX_VALUE;
        for (int a : as) min = Math.min(a, min);
        return min;
    }

    static void debug(Object... args) {
        StringJoiner j = new StringJoiner(" ");
        for (Object arg : args) {
            if (arg == null) j.add("null");
            else if (arg instanceof int[]) j.add(Arrays.toString((int[]) arg));
            else if (arg instanceof long[]) j.add(Arrays.toString((long[]) arg));
            else if (arg instanceof double[]) j.add(Arrays.toString((double[]) arg));
            else if (arg instanceof Object[]) j.add(Arrays.toString((Object[]) arg));
            else j.add(arg.toString());
        }
        System.err.println(j.toString());
    }

    static void printSingleLine(int[] array) {
        PrintWriter pw = new PrintWriter(System.out);
        for (int i = 0; i < array.length; i++) {
            if (i != 0) pw.print(" ");
            pw.print(array[i]);
        }
        pw.println();
        pw.flush();
    }

    static int lowerBound(int[] array, int value) {
        int lo = 0, hi = array.length, mid;
        while (lo < hi) {
            mid = (hi + lo) / 2;
            if (array[mid] < value) lo = mid + 1;
            else hi = mid;
        }
        return lo;
    }

    static int upperBound(int[] array, int value) {
        int lo = 0, hi = array.length, mid;
        while (lo < hi) {
            mid = (hi + lo) / 2;
            if (array[mid] <= value) lo = mid + 1;
            else hi = mid;
        }
        return lo;
    }
}
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