part two completed

AdventOfCode2025/AdventOfCode2025.csproj

@@ -28,6 +28,10 @@
       <Content Include="Input\DayFour.txt">
         <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
       </Content>
+      <None Remove="Input\DayFive.txt" />
+      <Content Include="Input\DayFive.txt">
+        <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+      </Content>
     </ItemGroup>
 
 </Project>

AdventOfCode2025/Cafeteria.cs

@@ -0,0 +1,80 @@
+using AdventOfCode2025.Utils;
+using Range = AdventOfCode2025.Utils.Range;
+
+namespace AdventOfCode2025;
+
+public class Cafeteria : IAdventSolution
+{
+    public AdventSolution Solve(string input)
+    {
+        var lines = input.SplitLines();
+
+        var ranges = new HashSet<Range>();
+        var startIndex = 0;
+        while (lines[startIndex].Contains('-'))
+        {
+            var line = lines[startIndex++];
+            var parts = line.Split('-');
+            var range = new Range(ulong.Parse(parts[0]), ulong.Parse(parts[1]));
+            AddRange(ranges, range);
+        }
+        
+        var fresh = 0;
+        for(; startIndex < lines.Length; startIndex++)
+        {
+            var line = lines[startIndex];
+            if (line.Contains('-'))
+                continue;
+
+            var num = ulong.Parse(line);
+            if(ranges.Any(x => x.IsInRange(num))) fresh++;
+        }
+        RemoveExtraRanges(ranges);
+        var totalFresh = 0UL;
+        foreach (var range in ranges)
+            totalFresh += range.InclusiveCount;
+        
+        return new AdventSolution(fresh.ToString(), totalFresh.ToString());
+    }
+
+    private void AddRange(HashSet<Range> ranges, Range range)
+    {
+        var first = ranges.FirstOrDefault(x => x.IsInRange(range.Min));
+        if (first != default)
+        {
+            ranges.Remove(first);
+            if(!first.IsInRange(range.Max)) 
+                first =  new Range(first.Min, range.Max);
+        }
+        else
+            first = range;
+        
+        var last = ranges.LastOrDefault(x => x.IsInRange(first.Max));
+        if (last != default)
+        {
+            ranges.Remove(last);
+            if (!last.IsInRange(first.Min))
+                last = new Range(first.Min,  last.Max);
+        }
+        else
+            last = first;
+        
+        ranges.Add(last);
+    }
+
+    private void RemoveExtraRanges(HashSet<Range> ranges)
+    {
+        var toRemove = new List<Range>();
+        foreach (var range in ranges)
+        {
+            if(ranges.Any(x => x != range && (x.IsInRange(range.Min) || x.IsInRange(range.Max))))
+                toRemove.Add(range);
+        }
+
+        foreach (var remove in toRemove)
+        {
+            ranges.Remove(remove);
+            AddRange(ranges, remove);
+        }
+    }
+}

AdventOfCode2025/GiftShop.cs

@@ -1,4 +1,5 @@
 using System.Text.RegularExpressions;
+using Range = AdventOfCode2025.Utils.Range;
 
 namespace AdventOfCode2025;
 
@@ -43,6 +44,4 @@ public class GiftShop : IAdventSolution
         var numbers = input.Split('-', StringSplitOptions.TrimEntries | StringSplitOptions.RemoveEmptyEntries);
         return new Range(ulong.Parse(numbers[0]), ulong.Parse(numbers[^1]));
     }
-}
-
-public record struct Range(ulong Min, ulong Max);
+}

AdventOfCode2025/Program.cs

@@ -12,4 +12,7 @@ var dayThreeInput = await File.ReadAllTextAsync("./Input/DayThree.txt");
 AdventSolver<Lobby>.Solve(dayThreeInput, 3, "Lobby");
 
 var dayFourInput = await File.ReadAllTextAsync("./Input/DayFour.txt");
-AdventSolver<PrintingDepartment>.Solve(dayFourInput, 4, "Printing Department");
+AdventSolver<PrintingDepartment>.Solve(dayFourInput, 4, "Printing Department");
+
+var dayFiveInput = await File.ReadAllTextAsync("./Input/DayFive.txt");
+AdventSolver<Cafeteria>.Solve(dayFiveInput, 4, "Cafeteria");

AdventOfCode2025/Utils/Range.cs

@@ -0,0 +1,8 @@
+namespace AdventOfCode2025.Utils;
+
+public record struct Range(ulong Min, ulong Max)
+{
+    public ulong InclusiveCount => Max - Min + 1;
+    
+    public bool IsInRange(ulong value) => value >= Min && value <= Max;
+}