RosettaCodeData/Task/Primality-by-trial-division/Ruby/primality-by-trial-division-4.rb
Ingy döt Net b83f433714 tasks a-s
2013-04-10 23:57:08 -07:00

3 lines
49 B
Ruby

def isprime(n)
'1'*n !~ /^1?$|^(11+?)\1+$/
end