#!/usr/bin/env ruby

def sort_ver(vers)
  vers.sort do |v1, v2|
    v1_info = v1.split(?.).map &:to_i
    v2_info = v2.split(?.).map &:to_i
    ord_found = 0

    while ord_found.zero? and not v1_info.empty? and not v2_info.empty?
      ord_found = v2_info.first <=> v1_info.first
      v1_info.shift
      v2_info.shift
    end

    if ord_found.zero?
      v2_info.size <=> v1_info.size
    else
      ord_found
    end
  end
end

vers = [
  "0.1.0",  "3.2.1", "2.2.3",
  "3.2",    "5.0",   "5.0.1",
  "0.1.1",  "0.1",   "4.2.0",
  "17.9.2", "4.20",  "18.7.3"
]

p vers, sort_ver(vers)