041 Pandigital prime.sf

#!/usr/bin/ruby

# Author: Trizen
# Date: 27 January 2017
# https://github.com/trizen

# https://projecteuler.net/problem=41

# Runtime: 0.133s

# It cannot be a 9-digit pandigital prime as it would be divisible by 3. (45 / 3 = 15)
# It cannot be a 8-digit pandigital prime as it would be divisible by 3. (36 / 3 = 12)

for n in (1..7 -> flip) {
    var prime = 0

    @(1..n -> flip).permutations { |*p|
        var k = Num(p.join)

        if (k.is_prime) {
            prime = k
            break
        }
    }

    if (prime != 0) {
        say "#{n}-digit pandigital prime: #{prime}"
        break
    }
}