[2k25] Add day 1

AdventOfCode.csproj

@@ -2,19 +2,20 @@
 
     <PropertyGroup>
         <OutputType>Exe</OutputType>
-        <TargetFramework>net8.0</TargetFramework>
+        <TargetFramework>net10.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
+        <LangVersion>latest</LangVersion>
     </PropertyGroup>
 
     <ItemGroup>
-      <PackageReference Include="BenchmarkDotNet" Version="0.13.2" />
-      <PackageReference Include="Spectre.Console" Version="0.45.0" />
+      <PackageReference Include="BenchmarkDotNet" Version="0.15.8" />
+      <PackageReference Include="Spectre.Console" Version="0.54.0" />
     </ItemGroup>
 
     <ItemGroup>
-      <None Remove="Inputs\Day1.txt" />
-      <EmbeddedResource Include="Inputs\Day1.txt" />
+      <None Remove="Inputs\*" />
+      <EmbeddedResource Include="Inputs\*" />
     </ItemGroup>
 
 </Project>

Days/Day1.cs

@@ -5,96 +5,83 @@ namespace AdventOfCode.Days;
 public class Day1 : Day
 {
     public override int Number => 1;
-    public override string Name => "Trebuchet?!";
-
-    private static readonly (string, int)[] WrittenDigits =
-    [
-        ("one"  , 1),
-        ("two"  , 2),
-        ("three", 3),
-        ("four" , 4),
-        ("five" , 5),
-        ("six"  , 6),
-        ("seven", 7),
-        ("eight", 8),
-        ("nine" , 9)
-    ];
+    public override string Name => "Secret Entrance";
 
     public override void RunPart1(bool display = true)
     {
-        var calibrationSum = 0;
+        var password = 0;
+        var dialPosition = 50;
 
-        foreach (var line in Input.AsSpan().EnumerateLines())
+        foreach (var line in Input.EnumerateLines())
         {
-            var firstDigitIndex = line.IndexOfAnyInRange('0', '9');
-            var lastDigitIndex = line.LastIndexOfAnyInRange('0', '9');
+            var direction = line[0];
+            var offset = int.Parse(line[1..]);
 
-            var firstDigit = line[firstDigitIndex] - '0';
-            var lastDigit = line[lastDigitIndex] - '0';
+            var sign = direction is 'L'
+                ? -1
+                : +1;
 
-            calibrationSum += firstDigit * 10 + lastDigit;
+            dialPosition = MathMod(dialPosition + (offset * sign), 100);
+
+            if (dialPosition is 0)
+            {
+                password++;
+            }
         }
 
         if (display)
         {
-            AnsiConsole.MarkupLine($"[green]Sum of calibration values is: [yellow]{calibrationSum}[/][/]");
+            AnsiConsole.MarkupLine($"[green]Safe password is: [yellow]{password}[/][/]");
         }
     }
 
     public override void RunPart2(bool display = true)
     {
-        var calibrationSum = 0;
+        var password = 0;
+        var dialPosition = 50;
 
-        foreach (var line in Input.AsSpan().EnumerateLines())
+        foreach (var line in Input.EnumerateLines())
         {
-            var minFirstDigitIndex = line.IndexOfAnyInRange('0', '9');
-            var maxLastDigitIndex = line.LastIndexOfAnyInRange('0', '9');
+            var direction = line[0];
+            var offset = int.Parse(line[1..]);
 
-            var firstDigitValue = 0;
-            if (minFirstDigitIndex == -1)
+            var originalSign = Math.Sign(dialPosition);
+
+            var sign = direction is 'L'
+                ? -1
+                : +1;
+
+            dialPosition = dialPosition + (offset * sign);
+
+            int clickCount;
+            if (dialPosition is 0)
             {
-                minFirstDigitIndex = int.MaxValue;
+                clickCount = 1;
             }
             else
             {
-                firstDigitValue = line[minFirstDigitIndex] - '0';
-            }
+                clickCount = Math.Abs(dialPosition) / 100; // Number of times the dial passed by 0
 
-            var lastDigitValue = 0;
-            if (maxLastDigitIndex == -1)
-            {
-                maxLastDigitIndex = int.MinValue;
-            }
-            else
-            {
-                lastDigitValue = line[maxLastDigitIndex] - '0';
-            }
-
-            foreach (var (writtenDigit, value) in WrittenDigits)
-            {
-                var firstWrittenDigitIndex = line.IndexOf(writtenDigit);
-
-                if (firstWrittenDigitIndex != -1 && firstWrittenDigitIndex < minFirstDigitIndex)
+                // If we did a loop around it counts as a "click" too
+                if (originalSign != 0 && originalSign != Math.Sign(dialPosition))
                 {
-                    minFirstDigitIndex = firstWrittenDigitIndex;
-                    firstDigitValue = value;
-                }
-
-                var lastWrittenDigitIndex = line.LastIndexOf(writtenDigit);
-
-                if (lastWrittenDigitIndex != -1 && lastWrittenDigitIndex > maxLastDigitIndex)
-                {
-                    maxLastDigitIndex = lastWrittenDigitIndex;
-                    lastDigitValue = value;
+                    clickCount++;
                 }
             }
 
-            calibrationSum += 10 * firstDigitValue + lastDigitValue;
+            dialPosition = MathMod(dialPosition, 100);
+
+            password += clickCount;
         }
 
         if (display)
         {
-            AnsiConsole.MarkupLine($"[green]Sum of calibration values is: [yellow]{calibrationSum}[/][/]");
+            AnsiConsole.MarkupLine($"[green]Safe password is: [yellow]{password}[/][/]");
         }
     }
+
+    private static int MathMod(int left, int right)
+    {
+        return (Math.Abs(left * right) + left) % right;
+    }
 }

StringExtensions.cs

@@ -1,6 +1,6 @@
 namespace AdventOfCode;
 
-public static partial class StringExtensions
+public static class StringExtensions
 {
     public static IEnumerable<string> ReadAllLines(this StringReader reader)
     {
@@ -14,4 +14,25 @@ public static partial class StringExtensions
     {
         return new StringReader(text).ReadAllLines();
     }
+
+    public static char[,] AsCharGrid(this string text)
+    {
+        var lines = text.ReadAllLines().ToArray();
+        var lineCount = lines.Length;
+        var columnCount = lines[0].Length;
+
+        var grid = new char[lineCount, columnCount];
+
+        for (int i = 0; i < lineCount; i++)
+        {
+            var line = lines[i];
+
+            for (int j = 0; j < columnCount; j++)
+            {
+                grid[i, j] = line[j];
+            }
+        }
+
+        return grid;
+    }
 }