Python实现单链表

定义链表结构：

 class ListNode:
     def __init__(self, x):
         self.val = x
         self.next = None

输出该链表l1的元素：

while l1:
        print(l1.val)
        l1 = l1.next

将一个list的数据存为链表：

def list2listnode(num):
    head = ListNode(num[0])
    result = head
    for i in range(1,len(num)):
        head.next = ListNode(num[i])
        head = head.next
    return result