programming-elixir-1.6-chapter-6

modules_and_functions_6.exs

defmodule Chop do
  def guess(actual, range), do: guess_conditional(actual, range, div(Range.size(range),2))
  def guess_conditional(actual, range, current_guess) do
    if actual > 0 and actual <= Range.size(range) do
      guess_helper(actual, range, current_guess) 
    end
  end
  def guess_helper(actual, _, current_guess) when current_guess == actual do
    "#{current_guess}"
  end
  def guess_helper(actual, range, current_guess) when current_guess > actual do
    IO.puts "Is it #{current_guess} >"
    low.._//_ = range
    range = low..(current_guess)
    #IO.puts "#{range.first}..#{range.last}"
    guess_helper(actual, range, div(current_guess+low,2))
  end
  def guess_helper(actual, range, current_guess) when current_guess < actual do
    IO.puts "Is it #{current_guess} <"
    _..high//_ = range
    range = (current_guess)..high
    #IO.puts "#{range.first}..#{range.last}"
    guess_helper(actual, range, div(current_guess+high+1,2)) 
  end
end

modules_and_functions_6_found_solution.exs

defmodule Chop do
  def guess(actual, range = low..high//_) do
    guess = div(low+high, 2)
    IO.puts "Is it #{guess}?"
    _guess(actual, guess, range)
  end

defp _guess(actual, actual, _),
  do: IO.puts "Yes, it's #{actual}"

defp _guess(actual, guess, _..high//_)
  when guess < actual,
  do: guess(actual, guess+1..high)

defp _guess(actual, guess, low.._//_)
  when guess > actual,
  do: guess(actual, low..guess-1)
end