Completed day 5

AdvendOfCode.Runner/Program.cs

@@ -10,7 +10,7 @@ IChallange challange = Host.CreateDefaultBuilder()
     .Build()
     .Services
     .GetService<SolutionManager>()
-    .GetChallange(2024, 4);
+    .GetChallange(2024, 5);
 
 Console.WriteLine($"Part 1: {await challange.GetSolutionPart1()}");
 

AdventOfCode.Solutions/2024/Day 04/Day04.cs

@@ -33,7 +33,6 @@ namespace AdventOfCode.Solutions._2024
         //1888 
         public async Task<string> GetSolutionPart2()
         {
-            //_inputReader.SetSampleInput(true);
             Grid<Point> grid = await _inputReader.ReadToGrid<Point>();
             int total =  grid.FindWithValue('M').Where(p => IsValid(grid, p, 'S')).Count();
             total += grid.FindWithValue('S').Where(p => IsValid(grid, p, 'M')).Count();

AdventOfCode.Solutions/2024/Day 05/Day05.cs

@@ -0,0 +1,119 @@
+using AdventOfCode.Core.Shared.IO;
+
+namespace AdventOfCode.Solutions._2024
+{
+    public class Day05 : IChallange
+    {
+        public int Year => 2024;
+
+        public int Day => 5;
+
+        private readonly IInputReader _inputReader;
+
+        public Day05(IInputReader inputReader)
+        {
+            _inputReader = inputReader;
+            _inputReader.SetInput(this);
+        }
+
+        // 143
+        // 5651
+        public async Task<string> GetSolutionPart1()
+        {
+            int total = 0;
+            await foreach ((Rule[] rules, int[] updates) in GetUpdateWithRules(true))
+            {
+                total += updates[(updates.Length - 1) / 2];
+            }
+
+            return total.ToString();
+        }
+
+        // 123
+        // 4743
+        public async Task<string> GetSolutionPart2()
+        {
+            int total = 0;
+            await foreach ((Rule[] rules, int[] updates) in GetUpdateWithRules(false))
+            {
+                Rule[] requiredRules = rules;
+                int A = 0,
+                    runs = (updates.Length + 1) / 2;
+
+                for (int run = 0; run < runs; run++)
+                {
+                    int[] B = requiredRules.Select(r => r.B).Distinct().ToArray();
+                    A = requiredRules.Where(r => !B.Contains(r.A)).Select(r => r.A).First();
+                    requiredRules = requiredRules.Where(r => r.A != A).ToArray();
+                }
+
+                total += A;
+            }
+
+            return total.ToString();
+        }
+
+        private struct Rule
+        {
+            public int A { get; set; }
+            public int B { get; set; }
+        }
+
+        private async IAsyncEnumerable<(Rule[] rules, int[] updates)> GetUpdateWithRules(bool returnValidSet = true)
+        {
+            List<Rule> rules = [];
+            bool inputComplete = false;
+            await foreach (string updateString in _inputReader.ReadAsStringLine())
+            {
+                if (!inputComplete)
+                {
+                    if (string.IsNullOrEmpty(updateString))
+                        inputComplete = true;
+                    else
+                        rules.Add(ParseRule(updateString));
+                    continue;
+                }
+
+                int[] updatePages = updateString.Split(',').Select(int.Parse).ToArray();
+                Rule[] requiredRules = rules
+                    .Where(r => updatePages.Contains(r.A))
+                    .Where(r => updatePages.Contains(r.B))
+                    .ToArray();
+
+                if (IsValid(requiredRules, updatePages) == returnValidSet)
+                {
+                    yield return (requiredRules, updatePages);
+                }
+            }
+        }
+
+        private static bool IsValid(Rule[] rules, int[] updates)
+        {
+            Rule[] requiredRules = rules;
+            List<Rule> openRules = [];
+            foreach (int update in updates)
+            {
+                // check if the current update is in the required list as the second value, if so this is an invalid update
+                if (requiredRules.Any(r => r.B == update))
+                {
+                    return false;
+                }
+
+                // get new rules
+                openRules.AddRange(requiredRules.Where(r => r.A == update));
+                requiredRules = requiredRules.Where(r => r.A != update).ToArray();
+
+                // close open rules
+                openRules = openRules.Where(r => r.B != update).ToList();
+            }
+
+            return true;
+        }
+
+        private static Rule ParseRule(string input) 
+        {
+            int[] numbers = input.Split('|').Select(int.Parse).ToArray();
+            return new Rule { A = numbers[0], B = numbers[1] };
+        }
+    }
+}

AdventOfCode.Solutions/AdventOfCode.Solutions.csproj

@@ -34,6 +34,9 @@
     <Compile Update="2023\Day 13\Day13.cs">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </Compile>
+    <Compile Update="2024\Day 05\Day05.cs">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Compile>
     <Compile Update="2024\Day 04\Day04.cs">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </Compile>

AdventOfCode.Solutions/day-00-input.txt

@@ -1,10 +1,28 @@
-MMMSXXMASM
+47|53
-MSAMXMSMSA
+97|13
-AMXSXMAAMM
+97|61
-MSAMASMSMX
+97|47
-XMASAMXAMM
+75|29
-XXAMMXXAMA
+61|13
-SMSMSASXSS
+75|53
-SAXAMASAAA
+29|13
-MAMMMXMMMM
+97|29
-MXMXAXMASX
+53|29
+61|53
+97|53
+61|29
+47|13
+75|47
+97|75
+47|61
+75|61
+47|29
+75|13
+53|13
+
+75,47,61,53,29
+97,61,53,29,13
+75,29,13
+75,97,47,61,53
+61,13,29
+97,13,75,29,47