Bulls and cows: Difference between revisions

</pre>

=={{header|Elixir}}==

{{works with|Elixir|1.2}}

<lang elixir>defmodule Bulls_and_cows do

def play(size \\ 4) do

secret = Enum.take_random(1..9, size) |> Enum.map(&to_string/1)

play(size, secret)

end

defp play(size, secret) do

guess = input(size)

if guess == secret do

IO.puts "You win!"

else

{bulls, cows} = count(guess, secret)

IO.puts " Bulls: #{bulls}; Cows: #{cows}"

play(size, secret)

end

end

defp input(size) do

guess = IO.gets("Enter your #{size}-digit guess: ") |> String.strip

cond do

guess == "" ->

IO.puts "Give up"

exit(:normal)

String.length(guess)==size and String.match?(guess, ~r/^[1-9]+$/) ->

String.codepoints(guess)

true -> input(size)

end

end

defp count(guess, secret) do

Enum.zip(guess, secret) |>

Enum.reduce({0,0}, fn {g,s},{bulls,cows} ->

cond do

g == s -> {bulls + 1, cows}

g in secret -> {bulls, cows + 1}

true -> {bulls, cows}

end

end)

end

end

Bulls_and_cows.play</lang>

{{out}}

<pre>

Enter your 4-digit guess: 1234

Bulls: 1; Cows: 1

Enter your 4-digit guess: 5678

Bulls: 0; Cows: 2

Enter your 4-digit guess: 2345

Bulls: 0; Cows: 1

Enter your 4-digit guess: 1456

Bulls: 1; Cows: 0

Enter your 4-digit guess: 1782

You win!