2016 Update

Task/Remove-duplicate-elements/Elixir/remove-duplicate-elements.elixir

@@ -1,28 +1,27 @@
 defmodule RC do
-  # hash table approach
-  def uniq1(list) do
-    Enum.reduce(list, HashSet.new, fn x, set -> Set.put(set, x) end)
-    |> Set.to_list
-  end
+  # Set approach
+  def uniq1(list), do: MapSet.new(list) |> MapSet.to_list
 
   # Sort approach
-  def uniq2(list), do: Enum.sort(list) |> uniq2([])
-
-  defp uniq2([], uniq), do: Enum.reverse(uniq)
-  defp uniq2([h|t], uniq) when h==hd(uniq), do: uniq2(t, uniq)
-  defp uniq2([h|t], uniq)                 , do: uniq2(t, [h | uniq])
+  def uniq2(list), do: Enum.sort(list) |> Enum.dedup
 
   # Go through the list approach
   def uniq3(list), do: uniq3(list, [])
 
-  defp uniq3([], uniq), do: Enum.reverse(uniq)
-  defp uniq3([h|t], uniq) do
-    if Enum.member?(uniq, h), do: uniq3(t, uniq), else: uniq3(t, [h | uniq])
+  defp uniq3([], res), do: Enum.reverse(res)
+  defp uniq3([h|t], res) do
+    if h in res, do: uniq3(t, res), else: uniq3(t, [h | res])
   end
 end
 
-list = [1,1,2,1,'redundant',[1,2,3],[1,2,3],'redundant']
-IO.inspect Enum.uniq(list)
-IO.inspect RC.uniq1(list)
-IO.inspect RC.uniq2(list)
-IO.inspect RC.uniq3(list)
+num = 10000
+max = div(num, 10)
+list = for _ <- 1..num, do: :rand.uniform(max)
+funs = [&Enum.uniq/1, &RC.uniq1/1, &RC.uniq2/1, &RC.uniq3/1]
+Enum.each(funs, fn fun ->
+  result = fun.([1,1,2,1,'redundant',1.0,[1,2,3],[1,2,3],'redundant',1.0])
+  :timer.tc(fn ->
+    Enum.each(1..100, fn _ -> fun.(list) end)
+  end)
+  |> fn{t,_} -> IO.puts "#{inspect fun}:\t#{t/1000000}\t#{inspect result}" end.()
+end)