Data commit

Task/Topswops/Elixir/topswops.elixir

@@ -0,0 +1,24 @@
+defmodule Topswops do
+  def get_1_first( [1 | _t] ), do: 0
+  def get_1_first( list ), do: 1 + get_1_first( swap(list) )
+
+  defp swap( [n | _t]=list ) do
+    {swaps, remains} = Enum.split( list, n )
+    Enum.reverse( swaps, remains )
+  end
+
+  def task do
+    IO.puts "N\ttopswaps"
+    Enum.map(1..10, fn n -> {n, permute(Enum.to_list(1..n))} end)
+    |> Enum.map(fn {n, n_permutations} -> {n, get_1_first_many(n_permutations)} end)
+    |> Enum.map(fn {n, n_swops} -> {n, Enum.max(n_swops)} end)
+    |> Enum.each(fn {n, max} -> IO.puts "#{n}\t#{max}" end)
+  end
+
+  def get_1_first_many( n_permutations ), do: (for x <- n_permutations, do: get_1_first(x))
+
+  defp permute([]), do: [[]]
+  defp permute(list), do: for x <- list, y <- permute(list -- [x]), do: [x|y]
+end
+
+Topswops.task