49 lines
920 B
Ruby
49 lines
920 B
Ruby
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def divisors(n)
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divisors = [1]
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(2..Math.sqrt(n)).each do |possible_divisor|
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if n % possible_divisor == 0
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divisors << possible_divisor
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divisors << (n / possible_divisor)
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end
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end
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divisors.uniq
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end
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def abundant?(num)
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divisors(num).inject(:+) > num
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end
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def abundants
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[].tap do |abundants|
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(1..28122).each do |num|
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abundants << num if abundant?(num)
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end
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end
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end
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def sums_of_abundants
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[].tap do |sums|
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abundant_list = abundants
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abundant_list.each_with_index do |num, index|
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abundant_list.drop(index).each do |second_num|
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sum = num + second_num
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if sum < 28123
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sums << sum
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else
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break
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end
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end
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end
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end
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end
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def not_sums_of_abundants
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non_abundants = (1..28122).to_a
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sums_of_abundants.uniq.each do |sum|
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non_abundants.delete sum
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end
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non_abundants
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end
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puts not_sums_of_abundants.inject(:+)
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