Day 2 solution in C#

.gitignore

@@ -1 +1,5 @@
 /target
+/.vs/
+*.user
+/bin/
+/obj/

advent-of-code-2021.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+	<PropertyGroup>
+		<OutputType>Exe</OutputType>
+		<TargetFramework>net6.0</TargetFramework>
+		<RootNamespace>aoc2021</RootNamespace>
+		<ImplicitUsings>enable</ImplicitUsings>
+		<Nullable>enable</Nullable>
+		<ProduceReferenceAssembly>False</ProduceReferenceAssembly>
+		<EnforceCodeStyleInBuild>True</EnforceCodeStyleInBuild>
+	</PropertyGroup>
+
+	<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
+	  <WarningLevel>5</WarningLevel>
+	  <TreatWarningsAsErrors>True</TreatWarningsAsErrors>
+	</PropertyGroup>
+
+	<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
+	  <WarningLevel>5</WarningLevel>
+	  <TreatWarningsAsErrors>True</TreatWarningsAsErrors>
+	</PropertyGroup>
+
+	<ItemGroup>
+	  <None Update="inputs\02.txt">
+	    <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+	  </None>
+	</ItemGroup>
+
+</Project>

advent-of-code-2021.sln

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+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.0.31903.59
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "advent-of-code-2021", "advent-of-code-2021.csproj", "{1B54D933-507B-4F44-9BE3-F1794B593AF7}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{1B54D933-507B-4F44-9BE3-F1794B593AF7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{1B54D933-507B-4F44-9BE3-F1794B593AF7}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{1B54D933-507B-4F44-9BE3-F1794B593AF7}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{1B54D933-507B-4F44-9BE3-F1794B593AF7}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {17D280F0-AD9F-481E-8687-28AAB4A54437}
+	EndGlobalSection
+EndGlobal

src/02.cs

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+namespace aoc2021
+{
+    internal class Day02
+    {
+        internal static void Go()
+        {
+            var lines = File.ReadAllLines("inputs/02.txt");
+            var instructions = new List<Instruction>();
+            foreach (var instruction in lines)
+            {
+                var fmt = instruction.Split(' ');
+                instructions.Add(new Instruction()
+                {
+                    Direction = fmt[0],
+                    Amount = Convert.ToInt64(fmt[1]),
+                });
+            }
+
+            Part1(instructions);
+            Part2(instructions);
+        }
+
+        struct Instruction
+        {
+            public string Direction;
+            public long Amount;
+        }
+
+        struct Position
+        {
+            public long h;
+            public long d;
+        }
+
+        private static void Part1(IEnumerable<Instruction> instructions)
+        {
+            Position pos = new();
+            using (var t = new Timer())
+            {
+                foreach (var instruction in instructions)
+                {
+                    switch (instruction.Direction)
+                    {
+                        case "forward":
+                            pos.h += instruction.Amount;
+                            break;
+
+                        case "down":
+                            pos.d += instruction.Amount;
+                            break;
+
+                        case "up":
+                            pos.d -= instruction.Amount;
+                            break;
+                    }
+                }
+            }
+
+            Logger.Log($"part1: h: {pos.h}, d: {pos.d}, result: {pos.h * pos.d}");
+        }
+
+        private static void Part2(IEnumerable<Instruction> instructions)
+        {
+            Position pos = new();
+            using (var t = new Timer())
+            {
+                long aim = 0;
+                foreach (var instruction in instructions)
+                {
+                    switch (instruction.Direction)
+                    {
+                        case "forward":
+                            pos.h += instruction.Amount;
+                            pos.d += aim * instruction.Amount;
+                            break;
+
+                        case "down":
+                            aim += instruction.Amount;
+                            break;
+
+                        case "up":
+                            aim -= instruction.Amount;
+                            break;
+                    }
+                }
+            }
+
+            Logger.Log($"part2: h: {pos.h}, d: {pos.d}, result: {pos.h * pos.d}");
+        }
+    }
+}

src/Logger.cs

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+using System.Diagnostics;
+
+namespace aoc2021
+{
+    internal class Logger
+    {
+        public static void Log(string msg)
+        {
+            Console.WriteLine(msg);
+            Debug.WriteLine(msg);
+        }
+    }
+}

src/Timer.cs

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+using System.Diagnostics;
+
+namespace aoc2021
+{
+    internal class Timer : IDisposable
+    {
+        private readonly Stopwatch stopwatch = Stopwatch.StartNew();
+        public void Dispose()
+        {
+            stopwatch.Stop();
+            var (elapsed, unit) = ConvertElapsedToHumanReadable();
+            Logger.Log($"Took {elapsed:N1}{unit}");
+        }
+
+        public (double elapsed, string unit) ConvertElapsedToHumanReadable()
+        {
+            return ConvertElapsedToHumanReadable(stopwatch.ElapsedTicks, Stopwatch.Frequency);
+        }
+
+        public static (double elapsed, string unit) ConvertElapsedToHumanReadable(double ticks, long frequency)
+        {
+            var elapsed = 1.0d * ticks / frequency;
+            var unit = "s";
+            if (elapsed < 0.001)
+            {
+                elapsed *= 1e+6;
+                unit = "us";
+            }
+            else if (elapsed < 1)
+            {
+                elapsed *= 1000;
+                unit = "ms";
+            }
+            else if (elapsed < 60)
+            {
+                unit = "s";
+            }
+            else if (elapsed < 60 * 60)
+            {
+                elapsed /= 60;
+                unit = "m";
+            }
+
+            return (elapsed, unit);
+        }
+    }
+}

src/main.cs

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+aoc2021.Day02.Go();