Add Day 7

.vscode/launch.json

@@ -69,6 +69,17 @@
             "cwd": "${workspaceFolder}",
             "stopAtEntry": false,
             "console": "internalConsole"
+        },
+        {
+            "name": "aoc-2024-07 Debug",
+            "type": "coreclr",
+            "request": "launch",
+            "preLaunchTask": "dotnet: build aoc-2024-07",
+            "program": "${workspaceFolder}/artifacts/bin/aoc-2024-07/debug/aoc-2024-07.dll",
+            "args": ["part-two", "data/2024/07/dev.txt"],
+            "cwd": "${workspaceFolder}",
+            "stopAtEntry": false,
+            "console": "internalConsole"
         }
     ]
 }

.vscode/tasks.json

@@ -50,6 +50,14 @@
             "group": "build",
             "problemMatcher": [],
             "label": "dotnet: build aoc-2024-06"
+        },
+        {
+            "type": "dotnet",
+            "task": "build aoc-2024-07.csproj",
+            "file": "src/2024/07/aoc-2024-07.csproj",
+            "group": "build",
+            "problemMatcher": [],
+            "label": "dotnet: build aoc-2024-07"
         }
     ]
 }

AdventOfCode.sln

@@ -17,6 +17,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "aoc-2024-05", "src\2024\05\
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "aoc-2024-06", "src\2024\06\aoc-2024-06.csproj", "{EEC6EF36-EE16-4DB4-9AE8-CF0234751458}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "aoc-2024-07", "src\2024\07\aoc-2024-07.csproj", "{58941BB2-E4AC-40F0-AA92-BEF51DEFC859}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -50,6 +52,10 @@ Global
 		{EEC6EF36-EE16-4DB4-9AE8-CF0234751458}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{EEC6EF36-EE16-4DB4-9AE8-CF0234751458}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{EEC6EF36-EE16-4DB4-9AE8-CF0234751458}.Release|Any CPU.Build.0 = Release|Any CPU
+		{58941BB2-E4AC-40F0-AA92-BEF51DEFC859}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{58941BB2-E4AC-40F0-AA92-BEF51DEFC859}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{58941BB2-E4AC-40F0-AA92-BEF51DEFC859}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{58941BB2-E4AC-40F0-AA92-BEF51DEFC859}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{FAF70800-E2C3-4AD7-B433-86C1F20380F7} = {37CA8017-085A-4F6A-BADB-535F929C10B9}
@@ -58,5 +64,6 @@ Global
 		{49021FCE-1CA9-430F-99B2-8E5C14A48394} = {37CA8017-085A-4F6A-BADB-535F929C10B9}
 		{D108A6AB-B974-4BD9-B97A-CB1D1A2F3920} = {37CA8017-085A-4F6A-BADB-535F929C10B9}
 		{EEC6EF36-EE16-4DB4-9AE8-CF0234751458} = {37CA8017-085A-4F6A-BADB-535F929C10B9}
+		{58941BB2-E4AC-40F0-AA92-BEF51DEFC859} = {37CA8017-085A-4F6A-BADB-535F929C10B9}
 	EndGlobalSection
 EndGlobal

src/2024/07/Program.cs

@@ -0,0 +1,81 @@
+using System.Buffers;
+using System.ComponentModel.DataAnnotations;
+using System.Globalization;
+
+using ConsoleAppFramework;
+
+var builder = ConsoleApp.Create();
+builder.Add("part-one", static ([Argument, FileExists] string file) =>
+{
+	Console.WriteLine($"Result: {ReadFile(file, true)}");
+});
+builder.Add("part-two", static ([Argument, FileExists] string file) =>
+{
+	Console.WriteLine($"Result: {ReadFile(file, false)}");
+});
+builder.Run(args);
+
+static long ReadFile(string file, bool simple)
+{
+	long result = 0;
+	using (var fileReader = new StreamReader(file))
+	{
+		ArrayBufferWriter<long> valueBuffer = new();
+		while (fileReader.ReadLine() is { } line)
+		{
+			valueBuffer.ResetWrittenCount();
+			var colon = line.IndexOf(':');
+			var expected = long.Parse(line.AsSpan(0, line.IndexOf(':')));
+			var valueSpan = line.AsSpan(colon + 1).Trim();
+			foreach (var valueRange in valueSpan.Split(' '))
+			{
+				var numberSpan = valueSpan[valueRange];
+				if (numberSpan.IsWhiteSpace())
+				{
+					continue;
+				}
+
+				valueBuffer.GetSpan(1)[0] = int.Parse(numberSpan, NumberStyles.None);
+				valueBuffer.Advance(1);
+			}
+
+			var values = valueBuffer.WrittenSpan;
+			if (IsValid(expected, values[..1], values[1..]))
+			{
+				result = checked(result + expected);
+			}
+		}
+	}
+
+	return result;
+
+	bool IsValid(long expected, ReadOnlySpan<long> results, in ReadOnlySpan<long> values)
+	{
+		if (values.Length == 0)
+		{
+			return results.Contains(expected);
+		}
+
+		var optionLength = simple ? 2 : 3;
+		var newResults = new long[results.Length * optionLength];
+		var factor = values[0];
+		var factorPow10 = (int)Math.Pow(10, (int)Math.Floor(Math.Log10(factor) + 1));
+
+		for (int i = 0; i < results.Length; i++)
+		{
+			var value = results[i];
+			((ReadOnlySpan<long>)[value + factor, value * factor]).CopyTo(newResults.AsSpan(i * optionLength, 2));
+			if (!simple)
+			{
+				newResults[i * optionLength + 2] = value * factorPow10 + factor;
+			}
+		}
+
+		return IsValid(expected, newResults, values[1..]);
+	}
+}
+
+class FileExistsAttribute : ValidationAttribute
+{
+	public override bool IsValid(object? value) => value is string path && File.Exists(path);
+}

src/2024/07/aoc-2024-07.csproj

@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <RootNamespace>aoc_2024_07</RootNamespace>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>