mirror of
https://github.com/TheAlgorithms/Ruby
synced 2024-12-25 21:58:57 +01:00
22 lines
537 B
Ruby
22 lines
537 B
Ruby
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# frozen_string_literal: true
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require_relative './square_root'
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require_relative './ceil'
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# Calculates the aliquot sum of a number (the sum of all proper divisors of a number)
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class AliquotSum
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class << self
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def call(number)
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divisors(number).sum
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end
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private
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def divisors(number)
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low_divisors = (1..Ceil.call(SquareRoot.call(number))).select { |num| (number % num).zero? }
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high_divisors = low_divisors.map { |div| number / div }
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(low_divisors + high_divisors).uniq - [number]
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end
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end
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end
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