Test bei Make.tv

maketv.rb

class Node
  attr_accessor :value, :next

  def initialize(value, _next)
    @value = value
    @next = _next
  end

  def to_s
    "#{self.value} -> #{self.next ? self.next.to_s : nil}"
  end
end

def reverse(n)
  prev, _next = nil, nil

  loop do
    _next = n.next
    n.next = prev
    prev = n

    if _next
      n = _next
    else
      break
    end
  end

  return n
end


_4 = Node.new(8, nil)
_3 = Node.new(4, _4)
_2 = Node.new(7, _3)
list = Node.new(1, _2)

# n         _next
# 1    ->     7    ->    4    ->    8
#
# 1    <-     7    <-    4    <-    8
puts list

x = reverse(list)

puts x