Module: Bases::Algorithms

Defined in:
lib/bases/algorithms.rb

Overview

This module encapsulates the practical algorithms used to change bases.

Class Method Summary collapse

Class Method Details

.convert_from_base(digits_ary, source_base) ⇒ Integer

Convert a value in a source base to an integer in base 10.

Parameters:

  • digits_ary (Array<String>) —

    An array of digits, from the most significant to the least significant.

  • source_base (Array<String>) —

    A base expressed as a list of digits

Returns:



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# File 'lib/bases/algorithms.rb', line 32

def self.convert_from_base(digits_ary, source_base)
  # The numeric base is the number of digits in the source base.
  numeric_base = source_base.count

  digits_ary.reduce(0) do |acc, digit|
    source_base.find_index(digit) + numeric_base * acc
  end
end

.convert_to_base(value, new_base) ⇒ Array<String>

The common base conversion algorithm, which converts a number in base 10 (value) to its value in base new_base.

Parameters:

Returns:

  • (Array<String>) —

    An array of digits (as strings) from the most significant to the least significant one



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# File 'lib/bases/algorithms.rb', line 11

def self.convert_to_base(value, new_base)
  # Return early if the is 0, as it is the first digit of the base array.
  return [new_base.first] if value == 0

  result = []
  numeric_base = new_base.count

  while value > 0
    remainder = value % numeric_base
    value /= numeric_base
    result.unshift(new_base[remainder])
  end

  result
end