AIプログラミング③

using System;
using System.Collections.Generic;
using System.Globalization;

class Program
{
    const uint A = 0x41C64E6D;
    const uint C = 0x3039;
    const int InitialConsume = 2;   //事前消費
    const int CompareCount = 10;

    static void Main()
    {
        Console.WriteLine("DQMJ2P 初期SEED絞り込みツール");
        Console.WriteLine();

        Console.Write("起動時間 (yyyy/MM/dd HH:mm:ss) 空欄 = 現在時刻: ");
        string timeInput = Console.ReadLine();

        DateTime baseTime;
        if (string.IsNullOrWhiteSpace(timeInput))
        {
            baseTime = DateTime.Now;
        }
        else
        {
            baseTime = DateTime.ParseExact(
                timeInput,
                "yyyy/MM/dd HH:mm:ss",
                CultureInfo.InvariantCulture
            );
        }

        Console.Write("観測値 (0～6 を10個まで、スペース区切り): ");
        string valueInput = Console.ReadLine();

        string[] tokens = valueInput.Split(' ', StringSplitOptions.RemoveEmptyEntries); //観測値のリスト

        List<int> observed = new List<int>();
        for (int i = 0; i < tokens.Length && i < CompareCount; i++)
        {
            observed.Add(int.Parse(tokens[i]));
        }

        Console.WriteLine();
        Console.WriteLine("Searching...");

        List<(uint init, uint current)> results = new List<(uint, uint)>();

        for (int sec = -60; sec <= 60; sec++)   //±1分の範囲
        {
            DateTime t = baseTime.AddSeconds(sec);
            uint initSeed = TimeToSeed(t);

            uint seed = initSeed;

            for (int i = 0; i < InitialConsume; i++)
            {
                seed = Next(seed);
            }

            bool match = true;
            uint current = seed;

            for (int i = 0; i < observed.Count; i++)
            {
                current = Next(current);
                int value = (int)((current >> 16) % 7);

                if (value == observed[i]) {}
                else
                {
                    match = false;
                    break;
                }
            }

            if (match)
            {
                results.Add((initSeed, current));
            }
        }

        Console.WriteLine();
        Console.WriteLine("Found " + results.Count + " candidates");

        for (int i = 0; i < results.Count; i++)
        {
            Console.WriteLine(
                "InitSeed=0x" + results[i].init.ToString("X8") +
                "  CurrentSeed=0x" + results[i].current.ToString("X8"));
        }
    }

    static uint Next(uint seed)
    {
        return unchecked(A * seed + C);
    }

    static uint TimeToSeed(DateTime time)
    {
        DateTime baseTime = new DateTime(
            2000, 1, 1, 0, 0, 0,
            DateTimeKind.Local
        );

        TimeSpan span = time - baseTime;
        long seconds = (long)span.TotalSeconds;

        return (uint)seconds;
    }
}