feat: start solving part 2

15/LensLibrary/Program.cs

@@ -19,35 +19,99 @@ public class Program
     }
 
     var input = await File.ReadAllTextAsync(args[0]);
-    var steps = input.Split(
-      ',',
-      StringSplitOptions.TrimEntries | StringSplitOptions.RemoveEmptyEntries
-    );
 
     var stopwatch = new Stopwatch();
     stopwatch.Start();
 
-    var total = 0;
-
-    foreach (var step in steps)
-    {
-      var stepValue = 0;
-
-      foreach (var character in step)
-      {
-        var ascii = (int)character;
-        stepValue += ascii;
-        stepValue *= 17;
-        stepValue %= 256;
-      }
-
-      total += stepValue;
-    }
+    var result = LaunchSequence
+      .Parse(input)
+      .Steps
+      .Sum(step => step.HashLabel());
 
     stopwatch.Stop();
 
-    Console.WriteLine($"The total is {total}. ({stopwatch.ElapsedMilliseconds}ms)");
+    Console.WriteLine($"The total is {result}. ({stopwatch.ElapsedMilliseconds}ms)");
 
-    return total;
+    return result;
   }
+}
+
+public class LaunchSequence(
+  List<Step> steps
+)
+{
+  public List<Step> Steps { get; init; } = steps;
+
+  public long Initialize()
+  {
+    var boxes = new Dictionary<int, Dictionary<string, int>>();
+
+    foreach (var num in Enumerable.Range(0, 255))
+    {
+      boxes.Add(num, []);
+    }
+
+    return 0;
+  }
+
+  public static LaunchSequence Parse(string input, bool part2 = false)
+  {
+    var steps = input
+      .Split(
+        ',',
+        StringSplitOptions.TrimEntries | StringSplitOptions.RemoveEmptyEntries
+      )
+      .Select(step => Step.Parse(step, part2))
+      .ToList();
+
+    return new LaunchSequence(steps);
+  }
+}
+
+public class Step(
+  string label,
+  Operation operation,
+  int? lensFocalLength
+)
+{
+  public string Label { get; init; } = label;
+  public Operation Operation { get; init; } = operation;
+  public int? LensFocalLength { get; init; } = lensFocalLength;
+
+  public int HashLabel() => Label
+    .Aggregate(0, (hash, character) =>
+    {
+      var ascii = (int)character;
+      hash += ascii;
+      hash *= 17;
+      hash %= 256;
+      return hash;
+    });
+
+  public static Step Parse(string input, bool part2 = false)
+  {
+
+    if (input.Contains('-'))
+    {
+      var label = part2 ? input.Trim('-') : input;
+      return new Step(label, Operation.Removal, null);
+    }
+
+    if (input.Contains('='))
+    {
+
+      var parts = input.Split('=');
+      var label = part2 ? parts[0] : parts[0] + "=" + parts[1];
+      var focalLength = int.Parse(parts[1]);
+      return new Step(label, Operation.Insertion, focalLength);
+    }
+
+    throw new ArgumentException("Invalid input.", nameof(input));
+  }
+}
+
+public enum Operation
+{
+  Removal,
+  Insertion,
 }