Hacker rank sock-merchant solution for elixir.

sock_merchant_elixir.ex

https://www.hackerrank.com/challenges/sock-merchant

defmodule Solution do
   def duplicate_socks() do
     read = IO.read :all
     [_ | result] = String.split(read, ~r/\W/, trim: true)
    
     #IO.write(:stdio, result)
   
     accum = find_duplication(result, %{})

     result = Enum.reduce(Map.keys(accum), 0, fn(key, acc) ->
       acc = acc + div(accum[key] , 2)
     end)
 
     IO.write(:stdio, result)
   end
   
  def find_duplication([head | tail], accumulator) do
    accumulator = if Map.has_key?(accumulator, head) do
      acc = accumulator[head] + 1
      Map.put(accumulator, head, acc)
    else
      Map.put(accumulator, head, 1)
    end
    find_duplication(tail, accumulator)
  end

  def find_duplication([], accumulator) do
    accumulator
  end

end
Solution.duplicate_socks()