project-euler/Sidef/174 Counting the number of hollow square laminae that can form one two three distinct arrangements.sf

#!/usr/bin/ruby

# Author: Trizen
# Date: 20 May 2017
# Translated: 16 November 2023
# https://github.com/trizen

# https://projecteuler.net/problem=174

# Runtime: 41.892s

var counts = Hash()
var tiles = 1_000_000

for k in (1 .. tiles>>2) {
    var sum = 0
    for j in (k+2 .. Inf `by` 2) {
        sum += (2*j + 2*(j - 2))
        sum <= tiles || break
        counts{sum} := 0 ++
    }
}

say counts.values.count {|value|
    value.is_between(1, 10)
}