11 lines
247 B
Ruby
11 lines
247 B
Ruby
require 'prime'
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digits = [9,8,7,6,5,4,3,2,1].to_a
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res = 1.upto(digits.size).flat_map do |n|
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digits.combination(n).filter_map do |set|
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candidate = set.join.to_i
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candidate if candidate.prime?
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end.reverse
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end
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puts res.join(",")
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