30 lines
482 B
Ruby
30 lines
482 B
Ruby
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require 'prime'
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def primes_up_to(n)
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Prime.take_while { |x| x < n }
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end
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def integer_rotations(n)
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rotations = []
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digits = n.to_s.split('')
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digits.count.times do
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rotations << digits.join('').to_i
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digits.rotate!
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end
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rotations
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end
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def is_circular?(n)
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circular = true
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integer_rotations(n).each do |perm|
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return false unless Prime.prime?(perm)
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end
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circular
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end
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def circular_primes_up_to(n)
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primes_up_to(n).select { |x| puts x; is_circular?(x) }
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end
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