armstrong numbers in ruby

armstrong_numbers.rb

# num = 1234
# num_length = Math.log(num, 10).ceil => 4
# base = 10 ** (num_length - 1) => 1000

def is_armstrong(num) 
    if (1..9).include?(num)
         return true
    elsif num == 10
        return false
    end
    num_c = num
    num_length = Math.log(num, 10).ceil
    len = num_length
    acc = []
    while len != 0
        base = 10 ** (len - 1)
        diff = (num_c / base)
        #puts "num: #{num}, numc: #{num_c}, len: #{len}, base: #{base}, diff: #{diff}"
        acc.push(diff ** num_length)
        num_c -= (diff * base)
        len -= 1
    end
    acc.reduce(:+) == num
end

(1..999).each do |n|
    if is_armstrong(n)
        puts "Number: #{n} => true"
    end
end