翻转链表的三种方法（python实现）

def func1(head):
p = head
q = head.next
p.next = None
while q:
r = q.next
q.next = p
p = q
q = r
return p

def func2(head):
p = head.next
while p.next:
q = p.next
p.next = q.next
head.next = q
q.next = p

p.next = head
head = head.next
p.next.next = None
return head

def func3(head):
if head.next == None:
return head
new_head = func3(head.next)
head.next.next = head
head.next = None
return new_head

#节点定义
class LNode:
def __init__(self, x):
self.val = x
self.next = None

#测试用例
if __name__ == '__main__':
l1 = LNode(3)
l1.next = LNode(2)
l1.next.next = LNode(1)
l1.next.next.next = LNode(99)
l = func3(l1)
print l.val, l.next.val, l.next.next.val, l.next.next.next.val