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-rw-r--r--2015/day10.exs18
1 files changed, 18 insertions, 0 deletions
diff --git a/2015/day10.exs b/2015/day10.exs
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+++ b/2015/day10.exs
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+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)}")