Day 10

1 files changed, 18 insertions, 0 deletions

diff --git a/2015/day10.exs b/2015/day10.exs
new file mode 100644
index 0000000..384a15f
--- /dev/null
+++ b/2015/day10.exs
@@ -0,0 +1,18 @@
+start = File.read!("inputs/day10.txt")
+
+lookAndSayStream =
+  Stream.iterate(start, fn current ->
+    Regex.scan(~r/(\d)\1*/, current)
+    |> Enum.map(fn [seq, _] ->
+      length = String.length(seq)
+      type = String.at(seq, 0)
+      "#{length}#{type}"
+    end)
+    |> Enum.join()
+  end)
+
+[fourtiethEntry] = Stream.drop(lookAndSayStream, 40) |> Enum.take(1)
+IO.puts("Fourtieth Entry Length: #{String.length(fourtiethEntry)}")
+
+[fiftiethEntry] = Stream.drop(lookAndSayStream, 50) |> Enum.take(1)
+IO.puts("Fiftieth Entry Length: #{String.length(fiftiethEntry)}")