feat: solve part 1 and part 2 of puzzle 6

06/WaitForIt.Tests/ProgramTests.cs

@@ -0,0 +1,16 @@
+namespace WaitForIt.Tests;
+
+public class ProgramTests
+{
+  public void Main_WhenGivenInput_ItShouldReturnTheProductOfTheMarginOfErrors()
+  {
+    var result = Program.Main(["INPUT.txt"]);
+    result.Should().Be(1710720);
+  }
+
+  public void Main_WhenGivenInputAndPart2_ItShouldReturnTheNumberOfWaysToWin()
+  {
+    var result = Program.Main(["INPUT.txt", "part2"]);
+    result.Should().Be(35349468);
+  }
+}

06/WaitForIt.Tests/PuzzleParserTests.cs

@@ -0,0 +1,38 @@
+namespace WaitForIt.Tests;
+
+public class PuzzleParserTests
+{
+  private readonly PuzzleParser _sut = new();
+
+  [Theory]
+  [MemberData(nameof(TestData.ValidInputData), MemberType = typeof(TestData))]
+  public void Parse_WhenGivenValidInput_ItShouldReturnAListOfRaces(string[] input, List<Race> expected)
+  {
+    var result = _sut.ParseRaces(input);
+    result.Should().BeEquivalentTo(expected);
+  }
+
+  public static class TestData
+  {
+    private static readonly string[] ValidInput =
+    [
+      "Time: 7 15 30",
+      "Distance: 9 40 200"
+    ];
+
+    public static IEnumerable<object[]> ValidInputData =>
+      new List<object[]>
+      {
+        new object[]
+        {
+          ValidInput,
+          new List<Race>
+          {
+            new(7, 9),
+            new(15, 40),
+            new(30, 200)
+          }
+        }
+      };
+  }
+}

06/WaitForIt.Tests/RaceTests.cs

@@ -0,0 +1,14 @@
+namespace WaitForIt.Tests;
+
+public class RaceTests
+{
+  [Theory]
+  [InlineData(7, 9, 4)]
+  [InlineData(15, 40, 8)]
+  [InlineData(30, 200, 9)]
+  public void CalculateNumberOfWaysToWin_WhenCalled_ItShouldReturnNumberOfWaysToWin(int raceDuration, int distanceRecord, int expected)
+  {
+    var result = new Race(raceDuration, distanceRecord).CalculateNumberOfWaysToWin();
+    result.Should().Be(expected);
+  }
+}

06/WaitForIt.Tests/UnitTest1.cs

@@ -1,10 +0,0 @@
-namespace WaitForIt.Tests;
-
-public class UnitTest1
-{
-    [Fact]
-    public void Test1()
-    {
-
-    }
-}

06/WaitForIt.Tests/WaitForIt.Tests.csproj

@@ -27,4 +27,10 @@
     <ProjectReference Include="..\WaitForIt\WaitForIt.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Content Include="..\INPUT.txt">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
+
 </Project>

06/WaitForIt/Program.cs

@@ -1,2 +1,127 @@
-// See https://aka.ms/new-console-template for more information
-Console.WriteLine("Hello, World!");
+namespace WaitForIt;
+
+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 parser = new PuzzleParser();
+    var input = await File.ReadAllLinesAsync(args[0]);
+
+    long result = args.Length > 1 && args[1] == "part2"
+      ? parser
+        .ParseRace(input)
+        .CalculateNumberOfWaysToWin()
+      : parser.ParseRaces(input)
+        .Select(r => r.CalculateNumberOfWaysToWin())
+        .Aggregate((long)1, (acc, curr) => acc * curr);
+
+    Console.WriteLine($"The product of the margin of errors is {result}.");
+
+    return (int)result;
+  }
+}
+
+/// <summary>
+/// Parses the puzzle input.
+/// </summary>
+public class PuzzleParser
+{
+  private List<long> GetValues(string input) => input
+    .Split(' ', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries)
+    .Skip(1)
+    .Select(long.Parse)
+    .ToList();
+
+  /// <summary>
+  /// Parses the puzzle input to list of races
+  /// </summary>
+  /// <param name="racesInput">The list of races</param>
+  /// <returns>A list containing instances of <see cref="Race"/>.</returns>
+  public List<Race> ParseRaces(string[] racesInput)
+  {
+    var races = new List<Race>();
+    var durations = GetValues(racesInput[0]);
+    var distances = GetValues(racesInput[1]);
+
+    if (durations.Count != distances.Count)
+    {
+      throw new ArgumentException("The number of times and distances must be equal.");
+    }
+
+    for (int i = 0; i < durations.Count; i++)
+    {
+      races.Add(new Race(durations[i], distances[i]));
+    }
+
+    return races;
+  }
+
+  /// <summary>
+  /// Parses the puzzle input as single race
+  /// </summary>
+  /// <param name="racesInput">The list of races</param>
+  /// <returns>An instance of <see cref="Race"/>.</returns>
+  public Race ParseRace(string[] racesInput)
+  {
+    var duration = string.Join("", GetValues(racesInput[0]).Select(v => v.ToString()));
+    var distance = string.Join("", GetValues(racesInput[1]).Select(v => v.ToString()));
+
+    return new Race(long.Parse(duration), long.Parse(distance));
+  }
+}
+
+/// <summary>
+/// Represents a Race
+/// </summary>
+/// <param name="duration">The duration of the race</param>
+/// <param name="distanceRecord">The distance record</param>
+/// <returns>An instance of <see cref="Race"/>.</returns> 
+public class Race(
+  long duration,
+  long distanceRecord
+)
+{
+  /// <summary>
+  /// Gets the duration of the race
+  /// </summary>
+  public long Duration { get; init; } = duration;
+
+  /// <summary>
+  /// Gets the distance record
+  /// </summary>
+  public long DistanceRecord { get; init; } = distanceRecord;
+
+  /// <summary>
+  /// Calculates the number of ways the race can be won.
+  /// </summary>
+  /// <returns>The number of ways the race can be won.</returns>
+  public long CalculateNumberOfWaysToWin()
+  {
+    var numberOfWaysToWin = 0;
+
+    for (var secsHeld = 0; secsHeld < Duration; secsHeld++)
+    {
+      var speed = 1 * secsHeld;
+      var distance = speed * (Duration - secsHeld);
+
+      if (distance > DistanceRecord)
+      {
+        numberOfWaysToWin++;
+      }
+    }
+
+    return numberOfWaysToWin;
+  }
+}