experimental-projects/factordb/batch_gcd_factor_2.sf

#!/usr/bin/ruby

# Factorize a list of numbers for FactorDB, given a main list and several other
# lists of numbers that may have a common factor with the numbers in the main list.

var nums = File(ARGV.shift).open_r.lines.map{.nums.last}.grep { defined(_) }.uniq

var gcds = Math.batch_gcd(
    [
        nums...,
        ARGV.map{ File(_).open_r.lines.map{.nums.last}.grep { defined(_) && (.len\\0 > 25) } }.flat...
    ].uniq.sort...
).uniq.sort

for n in (nums) {
    var f = Math.gcd_factors(n, gcds).first(-1)
    f || next
    say "#{n} = #{f.join(' * ')}"
}