http://www.perlmonks.org?node_id=147662


in reply to Luhn Number Golf

Here's a sub with 62 characters. Expects the number as an argument and returns 1 or 0. 

sub luhn {
#2345678901234567890123456789012345678901234567890123456789012
for(pop=~/(.)(.)/g){($a+=$1)+=$_ for map{split//}2*$2}!($a%10)
}

[download]
/prakash

In Section Meditations