project-euler/Sidef/060 Prime pair sets.sf

#!/usr/bin/ruby

# Author: Trizen
# Date: 18 March 2023
# https://github.com/trizen

# https://projecteuler.net/problem=60

# Runtime: 21.765s

var primes = 1e4.primes
say "Checking primes <= #{primes.tail}"

primes.each_kv {|i,p|

    var indx = []
    var good = [p]

    for (var j = i+1; true; ++j) {

        var q = primes[j] \\ do {
            break if indx.is_empty
            good.pop
            j = indx.pop
            next
        }

        var ok = true

        [q, good...].combinations(2, {|*a|
            (a.join.to_n.is_prime && a.flip.join.to_n.is_prime) || do {
                ok = false
                break
            }
        })

        if (ok) {

            good << q
            indx << j

            if (good.len == 5) {
                say "sum(#{good}) = #{good.sum}"
                goto :FINISH
            }
        }
    }
} @:FINISH