算法题/反转链表

输入一个链表，反转链表后，输出链表的所有元素。

思路：定义三个指针

node1指针指向原链表中第一个结点，且作为最后一个结点

node2指针.next指向node1结点

temp指针指向node2结点的下一个结点

#coding:utf-8
class LiseNode:
    def __init__(self,x):
        self.val = x
        self.next = None


class Solution:
    def ReverseList(self,pHead):
        if pHead is None:
            return pHead
        node1 = pHead
        node2 = pHead.next
        #node1结点为尾结点
        node1.next = None
        while node2 is not None:
            temp = node2.next
            node2.next = node1
            node1 = node2
            node2 = temp
        return node1

if __name__ == '__main__':
    node1 = LiseNode()
    node2 = LiseNode()
    node3 = LiseNode()
    node4 = LiseNode()
    node5 = LiseNode()
    node1.next = node2
    node2.next = node3
    node3.next = node4
    node4.next = node5
    node5.next = None
    s = Solution()
    print(s.ReverseList(node1).val)