project-euler/Sidef/119 Digit power sum.sf

#!/usr/bin/ruby

# Author: Trizen
# Date: 18 May 2017
# Translated: 16 November 2023
# https://github.com/trizen

# https://projecteuler.net/problem=119

# Runtime: 0.415s

define nth = 30

var terms = []
var prev = 0

for (var n = 1; true; ++n) {

    for k in (1..n) {
        if (n.ipow(k).sumdigits == n) {
            var t = n.ipow(k)
            t.len >= 2 || next
            terms << t
            say "#{n} -> #{n}^#{k} -> #{n.ipow(k)}"
        }
    }

    terms.sort!

    if (terms.len >= 2*nth) {
        terms[nth-1] == prev && break
        prev = terms[nth-1]
    }
}

say terms[nth-1]