結果

問題 No.1657 Sum is Prime (Easy Version)
ユーザー nishi5451nishi5451
提出日時 2021-09-07 17:29:37
言語 Java21
(openjdk 21)
結果
AC  
実行時間 100 ms / 2,000 ms
コード長 2,856 bytes
コンパイル時間 2,570 ms
コンパイル使用メモリ 78,676 KB
実行使用メモリ 40,900 KB
最終ジャッジ日時 2024-06-06 03:51:21
合計ジャッジ時間 5,947 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge1
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 88 ms
40,604 KB
testcase_01 AC 94 ms
40,588 KB
testcase_02 AC 97 ms
40,532 KB
testcase_03 AC 95 ms
40,584 KB
testcase_04 AC 94 ms
40,740 KB
testcase_05 AC 96 ms
40,460 KB
testcase_06 AC 94 ms
40,604 KB
testcase_07 AC 93 ms
40,652 KB
testcase_08 AC 96 ms
40,604 KB
testcase_09 AC 96 ms
40,496 KB
testcase_10 AC 90 ms
40,572 KB
testcase_11 AC 94 ms
40,452 KB
testcase_12 AC 95 ms
40,528 KB
testcase_13 AC 98 ms
40,360 KB
testcase_14 AC 100 ms
40,872 KB
testcase_15 AC 95 ms
40,652 KB
testcase_16 AC 93 ms
40,828 KB
testcase_17 AC 94 ms
40,400 KB
testcase_18 AC 93 ms
40,400 KB
testcase_19 AC 94 ms
40,532 KB
testcase_20 AC 96 ms
40,652 KB
testcase_21 AC 94 ms
40,496 KB
testcase_22 AC 92 ms
40,492 KB
testcase_23 AC 94 ms
40,900 KB
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ソースコード

diff # 

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

public class Main {
	static final int INF = 1<<30;
	static final long INFL = 1L<<60;
	static final int MOD = 1000000007;
	static final int MOD2 = 998244353;
	static List<List<Integer>> g;
	
	public static void main(String[] args) {
		FastScanner fs = new FastScanner();
		PrintWriter pw = new PrintWriter(System.out);
		// (b-a+1)*(a+b)/2
		// a+b = prime and b-a+1 = 2
		// a+b = prime and b = a+1
		// 2*a+1 = prime
		boolean[] table = new boolean[2000020];
		table[0] = table[1] = true;
		for(int i = 2; i < table.length; i++){
			if(!table[i]){
				for(int j = i+i; j < table.length; j += i) table[j] = true;
			}
		}
		int l = fs.nextInt();
		int r = fs.nextInt();
		int ans = 0;
		for(int i = l; i < r; i++){
			if(!table[2*i+1])	ans++;
		}
		for(int i = l; i <= r; i++){
			if(!table[i])	ans++;
		}
		pw.println(ans);
		pw.close();
	}
}

class FastScanner {
	private InputStream in = System.in;
	private byte[] buffer = new byte[1024];
	private int length = 0, p = 0;
	private boolean hasNextByte() {
		if (p < length) return true;
		else{
			p = 0;
			try{
				length = in.read(buffer);
			}catch(Exception e){
				e.printStackTrace();
			}
			if(length == 0) return false;
		}
		return true;
	}
	private int readByte() {
		if (hasNextByte() == true) return buffer[p++];
		return -1;
	}
	private static boolean isPrintable(int n) {
		return 33 <= n && n <= 126;
	}
	private void skip() {
		while (hasNextByte() && !isPrintable(buffer[p])) p++;
	}
	public boolean hasNext() {
		skip();
		return hasNextByte();
	}
	public String next() {
		if(!hasNext()) throw new NoSuchElementException();
		StringBuilder sb = new StringBuilder();
		int temp = readByte();
		while (isPrintable(temp)) {
			sb.appendCodePoint(temp);
			temp = readByte();
		}
		return sb.toString();
	}
	public int nextInt() {
		return Math.toIntExact(nextLong());
	}
	public int[] nextInts(int n) {
		int[] ar = new int[n];
		for (int i = 0; i < n; i++) ar[i] = nextInt();
		return ar;
	}
	public long[] nextLongs(int n) {
		long[] ar = new long[n];
		for (int i = 0; i < n; i++) ar[i] = nextLong();
		return ar;
	}
	public long nextLong() {
		if(!hasNext()) throw new NoSuchElementException();
		boolean minus = false;
		int temp = readByte();
		if (temp == '-') {
			minus = true;
			temp = readByte();
		}
		if (temp < '0' || '9' < temp) throw new NumberFormatException();
		long n = 0;
		while (isPrintable(temp)) {
			if ('0' <= temp && temp <= '9') {
				n *= 10;
				n += temp - '0';
			}
			temp = readByte();
		}
		return minus ? -n : n;
	}
	public char[] nextChars() {
		String s = next();
		return s.toCharArray();
	}
	public char[][] nextCharMat(int h, int w) {
		char[][] ar = new char[h][w];
		for(int i = 0; i < h; i++){
			String s = next();
			for(int j = 0; j < w; j++){
				ar[i][j] = s.charAt(j);
			}
		}
		return ar;
	}
}
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