func is_vampire (n) {
return [] if n.ilog10.is_even
var l1 = n.isqrt.ilog10.ipow10
var l2 = n.isqrt
var s = n.digits.sort.join
gather {
n.divisors.each { |d|
d < l1 && next
d > l2 && break
var t = n/d
next if (d%%10 && t%%10)
next if ("#{d}#{t}".sort != s)
take([d, t])
}
}
}
say "First 25 Vampire Numbers:"
with (1) { |i|
for (var n = 1; i <= 25; ++n) {
var fangs = is_vampire(n)
printf("%2d. %6s : %s\n", i++, n, fangs.join(' ')) if fangs
}
}
say "\nIndividual tests:"
[16758243290880, 24959017348650, 14593825548650].each { |n|
var fangs = is_vampire(n)
say "#{n}: #{fangs ? fangs.join(', ') : 'is not a vampire number'}"
}
Output:
First 25 Vampire Numbers:
1. 1260 : [21, 60]
2. 1395 : [15, 93]
3. 1435 : [35, 41]
4. 1530 : [30, 51]
5. 1827 : [21, 87]
6. 2187 : [27, 81]
7. 6880 : [80, 86]
8. 102510 : [201, 510]
9. 104260 : [260, 401]
10. 105210 : [210, 501]
11. 105264 : [204, 516]
12. 105750 : [150, 705]
13. 108135 : [135, 801]
14. 110758 : [158, 701]
15. 115672 : [152, 761]
16. 116725 : [161, 725]
17. 117067 : [167, 701]
18. 118440 : [141, 840]
19. 120600 : [201, 600]
20. 123354 : [231, 534]
21. 124483 : [281, 443]
22. 125248 : [152, 824]
23. 125433 : [231, 543]
24. 125460 : [204, 615] [246, 510]
25. 125500 : [251, 500]
Individual tests:
16758243290880: [1982736, 8452080], [2123856, 7890480], [2751840, 6089832], [2817360, 5948208]
24959017348650: [2947050, 8469153], [2949705, 8461530], [4125870, 6049395], [4129587, 6043950], [4230765, 5899410]
14593825548650: is not a vampire number