369 Plus One Linked List
369.Plus One Linked List
题目： https://leetcode.com/problems/plus-one-linked-list/
难度 : Medium
类似题目： plus one，plus one 用递归和循环写了，对于linked list，因为most significant digit在首位，递归写起来不方便，用循环尝试，然后代码并没有实质上的区别。
class Solution(object):
def plusOne(self, head):
"""
:type head: ListNode
:rtype: ListNode
"""
lst = []
cur = head
while cur:
lst.append(cur)
cur = cur.next
carry = 1
for i in range(len(lst)-1,-1,-1):
lst[i].val += carry
if lst[i].val < 10:
carry = 0
break
else:
lst[i].val -= 10
if carry == 1:
node = ListNode(1)
node.next = head
return node
else:
return head
