8 lines
322 B
Ruby
8 lines
322 B
Ruby
def validISBN13?(str)
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cleaned = str.delete("^0-9").chars
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return false unless cleaned.size == 13
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cleaned.each_slice(2).sum{|d1, d2| d1.to_i + 3*d2.to_i }.remainder(10) == 0
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end
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isbns = ["978-0596528126", "978-0596528120", "978-1788399081", "978-1788399083"]
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isbns.each{|isbn| puts "#{isbn}: #{validISBN13?(isbn)}" }
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