Day 3 solution

Took me a bit to remember how Aggregate worked, as it always does when I need it.

advent-of-code-2022.csproj

@@ -75,6 +75,8 @@
 	  <EmbeddedResource Include="inputs\25.txt" />
 	  <None Remove="inputs\02a.txt" />
 	  <EmbeddedResource Include="inputs\02a.txt" />
+	  <None Remove="inputs\03a.txt" />
+	  <EmbeddedResource Include="inputs\03a.txt" />
 	</ItemGroup>
 
 </Project>

inputs/03a.txt

@@ -0,0 +1,6 @@
+vJrwpWtwJgWrhcsFMMfFFhFp
+jqHRNqRjqzjGDLGLrsFMfFZSrLrFZsSL
+PmmdzqPrVvPwwTWBwg
+wMqvLMZHhHMvwLHjbvcjnnSBnvTQFn
+ttgJtRGJQctTZtZT
+CrZsJsPPZsGzwwsLwLmpwMDw

src/03.cs

@@ -0,0 +1,37 @@
+namespace aoc2022;
+
+internal class Day03 : Day
+{
+    private IEnumerable<string>? sacks;
+
+    internal override void Parse()
+    {
+        sacks = Util.ReadAllLines("03");
+    }
+
+    static int GetPriority(char x) => x <= 'Z' ? x - 'A' + 27 : x - 'a' + 1;
+
+    internal override string Part1()
+    {
+        var compartments = sacks!.Select(x => (x[..(x.Length/2)], x[(x.Length/2)..]));
+        var intersected = compartments.Select(x => x.Item1.Intersect(x.Item2).First());
+        var total = intersected.Select(GetPriority).Sum();
+
+        return $"Sum of duplicates' priorities: <+white>{total}";
+    }
+
+    internal override string Part2()
+    {
+        var groups = sacks!.Chunk(3);
+        var sum = groups.Sum(x =>
+            GetPriority(
+                x.Skip(1).Aggregate(
+                    x.First().AsEnumerable(),
+                    (l, e) => l.Intersect(e)
+                ).First()
+            )
+        );
+
+        return $"Sum of badges' priorities: <+white>{sum}";
+    }
+}