Elixir rosalind problem

[cpackingham]

Changes:
Added count_dna_nucleotides.exs

[abdouskamel]

This pull request has been forgotten. I am not able to review it, is there anyone who can ?

[OvermindDL1]

Hmm, I'd probably have written it like (as this is shorter and would run MUCH faster:

defmodule CountingDnaNuleotides do
  def count_dna_nucleotides(strand, acc \\ %{})
  def count_dna_nucleotides("", acc), do: acc
  def count_dna_nucleotides(<<c::binary-size(1), strand::binary>>, acc), do: count_dna_nucleotides(strand, Map.update(acc, c, 1, &(1+&1))
end

Or less cramped as:

defmodule CountingDnaNuleotides do
  def count_dna_nucleotides(strand, acc \\ %{})
  def count_dna_nucleotides("", acc), do: acc
  def count_dna_nucleotides(<<c::binary-size(1), strand::binary>>, acc) do
    count_dna_nucleotides(strand, Map.update(acc, c, 1, &(1+&1))
  end
end

And if you want to not accept invalid input then just on the final function add a guard of when c in ["A", "C", "G", "T"]