chopper_recursive_cleanup.rb

class ChopperRecursive
    def chop(x_number, array)
        if array.empty? or less_than_or_greater_to(x_number, array)
            -1
        end

        recurse(0, array.length - 1, x_number, array)
    end

    def recurse(low, high, x_number, array)
        middle = middle(low, high)
        
        if equal_to(array[middle], x_number)
            middle
        elsif greater_than(low, high)
            -1
        elsif less_than(array[middle], x_number)
            recurse(middle + 1, high, x_number, array)
        elsif greater_than(array[middle], x_number)
            recurse(low, middle - 1, x_number, array)
        else
            -1
        end
    end
    
    private
    
    def less_than_or_greater_to(number, array)
      number < array.first or number > array.last
    end
    
    def middle(low_number, high_number)
      (low + high)/2
    end
    
    def equal_to(first_number, second_number)
        first_number == second_number
    end
    
    def less_than(first_number, second_number)
      first_number < second_number
    end
    
    def greater_than(first_number, second_number)
      first_number > second_number
    end
end