2015 day 10

AOC.Test/Test2015.cs

@@ -15,6 +15,7 @@ public class Test2015
     [DataRow(typeof(Day07), "3176", "14710")]
     [DataRow(typeof(Day08), "1342", "2074")]
     [DataRow(typeof(Day09), "117", "909")]
+    [DataRow(typeof(Day10), "492982", "6989950")]
     public void TestAllDays(Type dayType, string part1, string part2)
     {
         Common.CheckDay(dayType, part1, part2);
@@ -30,6 +31,7 @@ public class Test2015
     // [DataRow(typeof(Day07), "", "")] // test input doesn't have "a" wire
     [DataRow(typeof(Day08), "12", "19")]
     [DataRow(typeof(Day09), "605", "982")]
+    [DataRow(typeof(Day10), "237746", "3369156")]
     public void CheckTestInputs(Type dayType, string part1, string part2)
     {
         Day.UseTestInput = true;

AOC2015/Day10.cs

@@ -5,11 +5,49 @@
 /// </summary>
 public sealed class Day10 : Day
 {
+    private string _seed;
+
     public Day10() : base(2015, 10, "Puzzle Name")
     {
+        _seed = Input.First();
     }
 
-    public override object Part1() => "";
+    public override object Part1()
+    {
+        for (var i = 0; i < 40; i++)
+            _seed = string.Concat(LookAndSay(_seed));
 
-    public override object Part2() => "";
+        return _seed.Length;
-}
+    }
+
+    public override object Part2()
+    {
+        for (var i = 0; i < 10; i++)
+            _seed = string.Concat(LookAndSay(_seed));
+
+        return _seed.Length;
+    }
+
+    public static IEnumerable<int> LookAndSay(string data)
+    {
+        var currentDigit = data[0];
+        int count = 1, place = 1;
+
+        while (place < data.Length)
+        {
+            if (data[place] == currentDigit) count++;
+            else
+            {
+                yield return count;
+                yield return currentDigit - '0';
+                currentDigit = data[place];
+                count = 1;
+            }
+
+            place++;
+        }
+
+        yield return count;
+        yield return currentDigit - '0';
+    }
+}

AOC2015/input2015/test10.in

@@ -0,0 +1 @@
+111221