Submission for the 2013-05-17 UpFront Wichita code challenge.

max_cycle_calc.rb

#!/usr/bin/env ruby

class CycleCalc
    def initialize(lowestN, highestN)
        @lowestN, @highestN = lowestN.to_i, highestN.to_i
    end
    def maxLength
        max = 0
        for n in @lowestN..@highestN
            l = cycleLength n
            max = l if l > max
        end
        max
    end
    def cycleLength(n)
        @length = 1
        transform n
        @length
    end
    def transform(n)
        return if n == 1
        @length = @length + 1
        if n % 2 === 0
            n = n / 2
        else
            n = n * 3 + 1
        end
        transform n unless n == 1
    end
end

c = CycleCalc.new(ARGV[0], ARGV[1])
puts ARGV[0] + " " + ARGV[1] + " " + c.maxLength.to_s