結果

問題 No.886 Direct
コンテスト
ユーザー uwi
提出日時 2019-09-13 22:44:08
言語 Java
(openjdk 23)
結果
AC  
実行時間 1,108 ms / 4,000 ms
コード長 4,649 bytes
コンパイル時間 3,824 ms
コンパイル使用メモリ 85,560 KB
実行使用メモリ 63,936 KB
最終ジャッジ日時 2024-07-04 10:07:23
合計ジャッジ時間 16,614 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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ファイルパターン 結果
sample AC * 4
other AC * 32
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 #
raw source code 

package contest190913;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;

public class E2 {
	InputStream is;
	PrintWriter out;
	String INPUT = "";
	
	void solve()
	{
		// a, b
		// gcd(a, b) = 1
		// sum (h-a)*(w-b)*2
		// + (h-1)w + w(h-1)
		
		// sum_(a,b) 1 (gcd(a,b)=1) = 
		
		long H = nl(), W = nl();
		int mod = 1000000007;
		
		int[] lpf = enumLowestPrimeFactors(3000050);
		int[] mob = enumMobiusByLPF(3000050, lpf);
		
		long C = 0;
		long B = 0;
		long A = 0;
		long AB = 0;
		for(int i = 1;i <= H && i <= W;i++) {
			C += mob[i] * (H/i) * (W/i); // const
			B += mob[i] * (H/i) * s1(W/i, mod) % mod * i;
			A += mob[i] * (W/i) * s1(H/i, mod) % mod * i;
			AB += mob[i] * s1(H/i, mod) * s1(W/i, mod) % mod * i % mod * i;
			C %= mod;
			B %= mod;
			A %= mod;
			AB %= mod;
		}
		long ans= (AB-A*W-B*H+C*H%mod*W)*2+(H-1)*W+(W-1)*H;
		ans %= mod;
		if(ans < 0)ans += mod;
		out.println(ans);
	}
	
	public static long s1(long n, int mod)
	{
		if(n % 2 == 0){
			return (n/2%mod)*((n+1)%mod)%mod;
		}else{
			return (n%mod)*((n+1)/2%mod)%mod;
		}
	}

	
	public static int[] enumMobiusByLPF(int n, int[] lpf)
	{
		int[] mob = new int[n+1];
		mob[1] = 1;
		for(int i = 2;i <= n;i++){
			int j = i/lpf[i];
			if(lpf[j] == lpf[i]){
//				mob[i] = 0;
			}else{
				mob[i] = -mob[j];
			}
		}
		return mob;
	}

	
	public static int[] enumLowestPrimeFactors(int n) {
		int tot = 0;
		int[] lpf = new int[n + 1];
		int u = n + 32;
		double lu = Math.log(u);
		int[] primes = new int[(int) (u / lu + u / lu / lu * 1.5)];
		for (int i = 2; i <= n; i++)
			lpf[i] = i;
		for (int p = 2; p <= n; p++) {
			if (lpf[p] == p)
				primes[tot++] = p;
			int tmp;
			for (int i = 0; i < tot && primes[i] <= lpf[p] && (tmp = primes[i] * p) <= n; i++) {
				lpf[tmp] = primes[i];
			}
		}
		return lpf;
	}

	
	
	
	
	void run() throws Exception
	{
		is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		out = new PrintWriter(System.out);
		
		long s = System.currentTimeMillis();
		solve();
		out.flush();
		if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
//		Thread t = new Thread(null, null, "~", Runtime.getRuntime().maxMemory()){
//			@Override
//			public void run() {
//				long s = System.currentTimeMillis();
//				solve();
//				out.flush();
//				if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
//			}
//		};
//		t.start();
//		t.join();
	}
	
	public static void main(String[] args) throws Exception { new E2().run(); }
	
	private byte[] inbuf = new byte[1024];
	public int lenbuf = 0, ptrbuf = 0;
	
	private int readByte()
	{
		if(lenbuf == -1)throw new InputMismatchException();
		if(ptrbuf >= lenbuf){
			ptrbuf = 0;
			try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
			if(lenbuf <= 0)return -1;
		}
		return inbuf[ptrbuf++];
	}
	
	private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
	private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
	
	private double nd() { return Double.parseDouble(ns()); }
	private char nc() { return (char)skip(); }
	
	private String ns()
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	
	private char[] ns(int n)
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while(p < n && !(isSpaceChar(b))){
			buf[p++] = (char)b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}
	
	private int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}
	
	private long[] nal(int n)
	{
		long[] a = new long[n];
		for(int i = 0;i < n;i++)a[i] = nl();
		return a;
	}
	
	private char[][] nm(int n, int m) {
		char[][] map = new char[n][];
		for(int i = 0;i < n;i++)map[i] = ns(m);
		return map;
	}
	
	private int[][] nmi(int n, int m) {
		int[][] map = new int[n][];
		for(int i = 0;i < n;i++)map[i] = na(m);
		return map;
	}
	
	private int ni() { return (int)nl(); }
	
	private long nl()
	{
		long num = 0;
		int b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); }
}
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