feat: solve part 1

07/CamelCards/CamelCards.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

07/CamelCards/Program.cs

@@ -0,0 +1,173 @@
+using System.Diagnostics;
+
+namespace CamelCards;
+
+
+public class Program
+{
+  public static async Task<int> Main(string[] args)
+  {
+    if (args.Length is 0)
+    {
+      Console.WriteLine("Please provide a path to the input file.");
+      return -1;
+    }
+
+    if (File.Exists(args[0]) is false)
+    {
+      Console.WriteLine("The provided file does not exist.");
+      return -2;
+    }
+
+    var input = await File.ReadAllLinesAsync(args[0]);
+
+    var stopWatch = new Stopwatch();
+    stopWatch.Start();
+
+    var result = input
+      .Select(Turn.Parse)
+      .OrderBy(t => t.Hand)
+      .Select((turn, index) => turn.Bid * (index + 1))
+      .Sum();
+
+    stopWatch.Stop();
+
+    Console.WriteLine($"The total winnings is {result}. ({stopWatch.ElapsedMilliseconds}ms)");
+
+    return result;
+  }
+}
+
+public class Turn(
+  Hand hand,
+  int bid
+)
+{
+  public Hand Hand { get; init; } = hand;
+  public int Bid { get; init; } = bid;
+
+  public override string ToString()
+  {
+    return $"{string.Join("", Hand.Cards.Select(c => c.Value))} {Bid}";
+  }
+
+  public static Turn Parse(string turnInput)
+  {
+    var parts = turnInput.Split(' ', StringSplitOptions.TrimEntries);
+    var cards = parts[0].Select(c => new Card(c)).ToList();
+    var bid = int.Parse(parts[1]);
+
+    return new Turn(new(cards), bid);
+  }
+}
+
+public class Hand : IComparable<Hand>
+{
+  public List<Card> Cards { get; init; }
+
+  public Hand(List<Card> cards)
+  {
+    if (cards.Count != 5)
+    {
+      throw new ArgumentException("A hand must have 5 cards");
+    }
+
+    Cards = cards;
+  }
+
+  public HandType Type => Cards.GroupBy(c => c.Value).Count() switch
+  {
+    5 => HandType.HighCard,
+    4 => HandType.OnePair,
+    3 => Cards.GroupBy(c => c.Value).Any(g => g.Count() == 3) ? HandType.ThreeOfAKind : HandType.TwoPair,
+    2 => Cards.GroupBy(c => c.Value).Any(g => g.Count() == 4) ? HandType.FourOfAKind : HandType.FullHouse,
+    1 => HandType.FiveOfAKind,
+    _ => throw new ApplicationException("Hand has no defined type"),
+  };
+
+  public int CompareTo(Hand? other)
+  {
+    int result;
+
+    if (other == null)
+    {
+      return 1;
+    }
+
+    result = Type.CompareTo(other.Type);
+
+    if (result != 0)
+    {
+      return result;
+    }
+
+    for (int i = 0; i < Cards.Count; i++)
+    {
+      var currentCard = Cards[i];
+      var otherCard = other.Cards[i];
+
+      var cardComparison = currentCard.Strength.CompareTo(otherCard.Strength);
+
+      if (i == Cards.Count - 1)
+      {
+        result = cardComparison;
+      }
+
+      if (cardComparison != 0)
+      {
+        result = cardComparison;
+        break;
+      }
+    }
+
+    return result;
+  }
+}
+
+public enum HandType
+{
+  HighCard,
+  OnePair,
+  TwoPair,
+  ThreeOfAKind,
+  FullHouse,
+  FourOfAKind,
+  FiveOfAKind,
+}
+
+
+public class Card
+{
+  private static readonly Dictionary<char, int> Cards = new()
+  {
+    ['A'] = 12,
+    ['K'] = 11,
+    ['Q'] = 10,
+    ['J'] = 9,
+    ['T'] = 8,
+    ['9'] = 7,
+    ['8'] = 6,
+    ['7'] = 5,
+    ['6'] = 4,
+    ['5'] = 3,
+    ['4'] = 2,
+    ['3'] = 1,
+    ['2'] = 0,
+  };
+
+  public char Value { get; init; }
+  public int Strength { get; init; }
+
+  public Card(char value)
+  {
+    var isValidCardChar = Cards.TryGetValue(value, out var strength);
+
+    if (!isValidCardChar)
+    {
+      throw new ArgumentException($"Invalid card value: {value}");
+    }
+
+    Value = value;
+    Strength = strength;
+  }
+}