Submission #1305079

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Source Code Expand

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

public class Hello
{
    static long N, K;
    public static void Main()
    {
        long[] NK = Console.ReadLine().Split(' ').Select(x => long.Parse(x)).ToArray();
        N = NK[0];
        K = NK[1];

        Boolean[] sent = new Boolean[N];

        Console.WriteLine(DFS(0, sent, K));
    }

    public static int DFS(long current, Boolean[] sent, long remains)
    {
        if(current == N)
        {
            if (remains == 0) return 1;
            return 0;
        }

        int ret = 0;

        for(int i = 0; i < N; i++)
        {
            if (sent[i]) continue;

            sent[i] = true;
            long nextRemains = remains;
            if (i != current) nextRemains--;
            ret += DFS(current + 1, sent, nextRemains);
            sent[i] = false;
        }
        return ret % 1777777777;
    }
}

Submission Info

Judge Result