2024 Day 1

src/2024/01/Program.cs

@@ -1,3 +1,15 @@
 using AdventOfCode.Common;
 
-var lines = Resources.GetResourceFileLines("input.txt");
+// Gather left and right lists
+(int[] Left, int[] Right) lists = Resources.GetInputFileLines("input.txt")
+    .Select(line => line.SplitToNumbers(" "))
+    .Aggregate((Array.Empty<int>(), Array.Empty<int>()), (lists, pair) => ([.. lists.Item1, pair.First()], [.. lists.Item2, pair.Last()]));
+
+var distances = from pair in lists.Left.Order().Zip(lists.Right.Order())
+                select Math.Abs(pair.First - pair.Second);
+
+var similarity = from left in lists.Left
+                 select lists.Right.Where(right => right == left).Count() * left;
+
+Console.WriteLine($"Part 1: {distances.Sum()}");
+Console.WriteLine($"Part 2: {similarity.Sum()}");

src/Common/Resources.cs

@@ -47,8 +47,8 @@ private static Stream GetResourceStream(Assembly assembly, string resourceFileNa
         return stream;
     }
 
-    public static int[] SplitToNumbers(this string csv) => csv
-        .SplitBy(",")
+    public static int[] SplitToNumbers(this string csv, string delimiter = ",") => csv
+        .SplitBy(delimiter)
         .Select(int.Parse)
         .ToArray();