Class: SubtractionOperationDifficultyCalculator

Inherits:
OperationDifficultyCalculator show all
Defined in:
lib/hypatia/difficulty-calculator.rb

Constant Summary collapse

DIFFICULTIES = 
{
  digit_zero: 1,    # difference of zero and any digit
  same_digits: 1,    # difference of same values digits
  even_even: 2,    # difference of even digits
  odd_odd: 2,    # difference of odd digits
  even_odd: 3,    # difference of even and odd digits
  borrow: 2,    # doing a borrow
  twodigit_digit: 4 # difference of two-digit number and digit
}

Instance Attribute Summary

Attributes inherited from OperationDifficultyCalculator

#difficulty

Instance Method Summary collapse

Methods inherited from OperationDifficultyCalculator

#initialize

Constructor Details

This class inherits a constructor from OperationDifficultyCalculator

Instance Method Details

#compute_difficulty ⇒ Object 



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# File 'lib/hypatia/difficulty-calculator.rb', line 67

def compute_difficulty
  if @numbers1.length < @numbers2.length
    @difficulty += DIFFICULTIES[:borrow]
  end
  @numbers1.reverse.each_with_index do | a , index |
    b = @numbers2.reverse[index]
    case
    when a == nil || b == nil
      @difficulty += DIFFICULTIES[:digit_zero]
    when a == 0 || b == 0
      if a == 0
        @difficulty += DIFFICULTIES[:borrow]
      end
      @difficulty += DIFFICULTIES[:digit_zero]
    when a == b
      @difficulty += DIFFICULTIES[:same_digits]
    when a < b
      @difficulty += DIFFICULTIES[:borrow]
    else
      @difficulty += DIFFICULTIES[:even_odd]
    end
  end
  @difficulty
end