Submission #7420182

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Source Code Expand

using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.Linq;
using static MyIO;


public class C
{
	public static void Main() => (new Solver()).Solve();
}


public class Solver
{
	public void Solve()
	{
		int N = GetInt();
		long K = GetLong();
		long[] A = GetLongs(N);

		var divisors = new List<long>((int)Math.Sqrt(K));
		for(long i = 1; i * i <= K; i++)
		{
			if(K % i == 0)
			{
				divisors.Add(i);
				if(i * i < K)
					divisors.Add(K / i);
			}
		}
		divisors.Sort();
		var dict = new Dictionary<long, long>();
		for(int i = 0; i < divisors.Count; i++)
			dict[divisors[i]] = i;

		long ans = 0;
		long[] cnt = new long[divisors.Count];
		for(int i = N - 1; i>= 0; i--)
		{
			long g = gcd(A[i], K);
			ans += cnt[dict[K / g]];
			for(int j = 0; j < divisors.Count; j++)
				if(A[i] % divisors[j] == 0)
					cnt[dict[divisors[j]]]++;
		}

		Console.WriteLine(ans);
	}

	private long gcd(long x, long y) => (y == 0) ? x : gcd(y, x % y);
}


public static class MyIO
{
	private static string[] args = null;
	private static int num = -1;
	private static int used = -1;

	private static string getArg()
	{
		if(used == num)
		{
			args = Console.ReadLine().Split(' ');
			num = args.Length;
			used = 0;
		}
		return args[used++];
	}

	public static int GetInt() => int.Parse(getArg());
	public static long GetLong() => long.Parse(getArg());
	public static double GetDouble() => double.Parse(getArg());
	public static string GetString() => getArg();
	public static char GetChar() => getArg()[0];
	public static int[] GetInts(int N) => Enumerable.Range(0, N).Select(_ => GetInt()).ToArray();
	public static long[] GetLongs(int N) => Enumerable.Range(0, N).Select(_ => GetLong()).ToArray();
	public static double[] GetDoubles(int N) => Enumerable.Range(0, N).Select(_ => GetDouble()).ToArray();
	public static string[] GetStrings(int N) => Enumerable.Range(0, N).Select(_ => GetString()).ToArray();
}

Submission Info

Judge Result