Submission #7853926


Source Code Expand

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


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


public class Solver
{
	public void Solve()
	{
		int MAX = 100000;
		int N = GetInt();
		int M = GetInt();
		int[] X = GetInts(N);

		int[] grpcnt = new int[M];
		int[] cnt = new int[MAX + 1];
		for(int i = 0; i < N; i++)
		{
			grpcnt[X[i] % M]++;
			cnt[X[i]]++;
		}

		int ans = grpcnt[0] / 2;
		if(M % 2 == 0)
			ans += grpcnt[M/2] / 2;

		for(int i = 1; i < (M + 1)/2; i++)
		{
			int a = i;
			int b = M - i;
			if(grpcnt[a] < grpcnt[b])
				swap(ref a, ref b);

			ans += grpcnt[b];

			int rest = grpcnt[a] - grpcnt[b];
			for(int j = a; j <= MAX; j += M)
			{
				int diff = Math.Min(rest, cnt[j]) / 2;
				ans += diff;
				rest -= diff * 2;
				if(rest < 2)
					break;
			}
		}

		Console.WriteLine(ans);
	}

	private void swap(ref int x, ref int y)
	{
		int tmp = x;
		x = y;
		y = tmp;
	}
}


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

Submission Time
Task D - Pair Cards
User DM7PvTyc
Language C# (Mono 4.6.2.0)
Score 700
Code Size 2062 Byte
Status AC
Exec Time 69 ms
Memory 23648 KB

Judge Result

Set Name sample all
Score / Max Score 0 / 0 700 / 700
Status
AC × 2
AC × 34
Set Name Test Cases
sample sample-01.txt, sample-02.txt
all sample-01.txt, sample-02.txt, 01-01.txt, 01-02.txt, 01-03.txt, 01-04.txt, 01-05.txt, 01-06.txt, 01-07.txt, 01-08.txt, 01-09.txt, 01-10.txt, 01-11.txt, 01-12.txt, 01-13.txt, 01-14.txt, 01-15.txt, 01-16.txt, 01-17.txt, 01-18.txt, 01-19.txt, 01-20.txt, 01-21.txt, 01-22.txt, 01-23.txt, 01-24.txt, 01-25.txt, 01-26.txt, 01-27.txt, 01-28.txt, 01-29.txt, 01-30.txt, sample-01.txt, sample-02.txt
Case Name Status Exec Time Memory
01-01.txt AC 24 ms 9440 KB
01-02.txt AC 65 ms 19552 KB
01-03.txt AC 66 ms 21600 KB
01-04.txt AC 69 ms 21600 KB
01-05.txt AC 67 ms 23648 KB
01-06.txt AC 66 ms 21600 KB
01-07.txt AC 67 ms 23520 KB
01-08.txt AC 65 ms 19552 KB
01-09.txt AC 67 ms 21600 KB
01-10.txt AC 67 ms 21728 KB
01-11.txt AC 66 ms 19936 KB
01-12.txt AC 65 ms 21600 KB
01-13.txt AC 66 ms 21856 KB
01-14.txt AC 67 ms 21600 KB
01-15.txt AC 66 ms 19552 KB
01-16.txt AC 66 ms 23648 KB
01-17.txt AC 65 ms 19552 KB
01-18.txt AC 66 ms 21600 KB
01-19.txt AC 65 ms 19680 KB
01-20.txt AC 67 ms 19936 KB
01-21.txt AC 66 ms 23520 KB
01-22.txt AC 66 ms 19552 KB
01-23.txt AC 65 ms 19552 KB
01-24.txt AC 66 ms 19552 KB
01-25.txt AC 66 ms 21728 KB
01-26.txt AC 66 ms 21984 KB
01-27.txt AC 45 ms 15968 KB
01-28.txt AC 26 ms 12372 KB
01-29.txt AC 25 ms 11616 KB
01-30.txt AC 25 ms 11872 KB
sample-01.txt AC 25 ms 13536 KB
sample-02.txt AC 25 ms 13536 KB