Exercício do Hacker Ranking - me deu bastante trabalho, porque o código dá timeout. Otimizei bastante, depois deu pra simplificar

Queue_with_two_stacks.rb

# Enter your code here. Read input from STDIN. Print output to STDOUT

class Queue
   
    def initialize
        @current_stack = []
        @aux_stack = []
    end
    
    def enqueue(x)
        @current_stack << x
    end
    
    def dequeue
        if @aux_stack.empty?
            while aux = @current_stack.pop
                @aux_stack << aux
            end
        end    
        element = @aux_stack.pop
    end
    
    def peek
        if @aux_stack.empty?
            while aux = @current_stack.pop
                @aux_stack << aux
            end
        end
        element = @aux_stack[-1]
    end
end

queue = Queue.new
res = []
q = gets.to_i
q.times do |i|
    type, x = gets.split(' ').map(&:to_i)
    case type
        when 1 then queue.enqueue(x)
        when 2 then queue.dequeue
        when 3 then res << queue.peek
    end
end
puts res.join("\n")