class Solution:
def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode:
dummy = p = ListNode(None)
add = 0
while l1 or l2 or add:
val = (l1.val if l1 else 0) + (l2.val if l2 else 0) + add
p.next = ListNode(val)
add = val//10
p = p.next
l1 = l1.next if l1 else None
l2 = l2.next if l2 else None
return dummy.next
class Solution:
def plusOne(self, digits: List[int]) -> List[int]:
n = len(digits)
add = 0
for i in range(n-1,-1,-1):
num = (digits[i] + 1 + add if i==n-1 else digits[i] + add)
digits[i] = num
add = num//10
if add == 0:
break
if add > 0:
digits.insert(0,1)
return digits
