Adv2015/D14.2/Program.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Text.RegularExpressions;

namespace D14._2
{
    public enum EnumState
    {
        Running, Resting
    };

    public class Reindeer
    {
        public int Speed;
        public int SpeedTime;
        public int RestTime;
        public string Name;

        public int Points = 0;
        public int DistanceTraveled = 0;
        public EnumState State = EnumState.Running;
        public int Remaining = 0;

        public override bool Equals(object obj)
        {
            var reindeer = obj as Reindeer;
            return reindeer != null &&
                   Name == reindeer.Name;
        }

        public override int GetHashCode()
        {
            return HashCode.Combine(Name);
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            if (args.Length < 1) throw new ArgumentException();
            if (File.Exists(args[0]) == false) throw new FileNotFoundException();

            var reindeers = new HashSet<Reindeer>();

            ParseFile(args[0], reindeers);

            for (int second = 0; second <= 2503; ++second)
            {
                int maxDistance = 0;
                foreach (var r in reindeers)
                {
                    if (r.State == EnumState.Running)
                    {
                        r.DistanceTraveled += r.Speed;
                        r.Remaining--;

                        if (r.Remaining == 0)
                        {
                            r.Remaining = r.RestTime;
                            r.State = EnumState.Resting;
                        }
                    }
                    else
                    {
                        r.Remaining--;
                        if (r.Remaining == 0)
                        {
                            r.Remaining = r.SpeedTime;
                            r.State = EnumState.Running;
                        }
                    }

                    if (r.DistanceTraveled > maxDistance) maxDistance = r.DistanceTraveled;
                }
                
                foreach (var r in reindeers)
                    if (r.DistanceTraveled == maxDistance) r.Points++;
            }

            int maxPoints = 0;
            foreach (var r in reindeers)
                if (r.Points > maxPoints) maxPoints = r.Points;

            Console.WriteLine($"The answer is : {maxPoints}");
        }

        private static void ParseFile(string f, HashSet<Reindeer> reindeers)
        {
            var regex = new Regex(@"(?<n>\w+) can fly (?<s>\d+) km/s for (?<st>\d+) seconds, but then must rest for (?<rt>\d+) seconds.");
            using (var file = File.OpenText(f))
            {
                while (true)
                {
                    var line = file.ReadLine();
                    if (line == null) break;

                    var result = regex.Match(line);
                    var r = new Reindeer();
                    r.Name = result.Groups["n"].Value;
                    r.Speed = int.Parse(result.Groups["s"].Value);
                    r.SpeedTime = int.Parse(result.Groups["st"].Value);
                    r.RestTime = int.Parse(result.Groups["rt"].Value);

                    r.Remaining = r.SpeedTime;

                    reindeers.Add(r);
                }
            }
        }
    }
}