算法題/反轉連結清單

輸入一個連結清單，反轉連結清單後，輸對外連結表的所有元素。

思路：定義三個指針

node1指針指向原連結清單中第一個結點，且作為最後一個結點

node2指針.next指向node1結點

temp指針指向node2結點的下一個結點

#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結點為尾結點
        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)