21 单链表逆置

class Node(object):
  def __init__(self, data=None, next=None):
    self.data = data
    self.next = next

link = Node(1, Node(2, Node(3, Node(4, Node(5, Node(6, Node(7, Node(8, Node(9)))))))))

def rev(link):
  pre = link
  cur = link.next
  pre.next = None
  while cur:
    tmp = cur.next
    cur.next = pre
    pre = cur
    cur = tmp
  return pre

root = rev(link)
while root:
  print root.data
  root = root.next

思路: http://blog.csdn.net/feliciafay/article/details/6841115

方法: http://www.xuebuyuan.com/2066385.html?mobile=1