guessing_game.exs

# Programming Elixir - exercise: ModulesAndFunctions-6
#
# Example:
#
#    iex(3)> GuessingGame.search(279, 0..1000)
#    is it 500
#    is it 250
#    is it 375
#    is it 312
#    is it 281
#    is it 265
#    is it 273
#    is it 277
#    279
#    :ok
#

defmodule GuessingGame do

  def midpoint(min..max) do
    div(min + max, 2)
  end

  def search(actual, range) do
    search(actual, range, midpoint(range))
  end

  def search(actual, min..max, guess)
    when guess < actual do
      IO.puts "is it #{guess}"
      search(actual, midpoint(min..max)..max)
  end

  def search(actual, _range, guess)
    when guess == actual do
      IO.puts actual
  end

  def search(actual, min..max, guess)
    when guess > actual do
      IO.puts "is it #{guess}"
      search(actual, min..midpoint(min..max))
  end

end