Python实现单链表中元素的反转_python_

class LNode:     def __init__(self, elem):         self.elem = elem         self.pnext = None   def reverse(head):     if head is None or head.pnext is None: #如果输入的链表是空或者只有一个结点，直接返回当前结点         return head     pre = None #用来指向上一个结点     cur = newhead = head #cur是当前的结点。newhead指向当前新的头结点     while cur:         newhead = cur         temp = cur.pnext         cur.pnext = pre #将当前的结点的指针指向前一个结点         pre = cur         cur = temp     return newhead   if __name__=="__main__":     head = LNode(1)     p1 = LNode(2)     p2 = LNode(3)     head.pnext = p1     p1.pnext = p2     p = reverse(head)     while p:         print(p.elem)         p = p.pnext

class LNode:     def __init__(self, elem):         self.elem = elem         self.pnext = None   def reverse(head):     if not head or not head.pnext:         return head     else:         newhead = reverse(head.pnext)         head.pnext.pnext = head #令下一个结点的指针指向当前结点         head.pnext = None #断开当前结点与下一个结点之间的指针指向联系，令其指向空         return newhead     if __name__=="__main__":     head = LNode(1)     p1 = LNode(2)     p2 = LNode(3)     head.pnext = p1     p1.pnext = p2     p = reverse(head)     while p:         print(p.elem)         p = p.pnext