def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode:
stack1 = []
stack2 = []
while l1:
stack1.append(l1.val)
l1 = l1.next
while l2:
stack2.append(l2.val)
l2 = l2.next
node = None
carry = 0
while stack1 or stack2:
x = stack1.pop() if stack1 else 0
y = stack2.pop() if stack2 else 0
val = x + y + carry
carry = val // 10
n = val % 10
cur = ListNode(n)
cur.next = node #!!!!!!!!!!!!!!!!!!尾插法
node = cur
# 判断最高位是否有进位
if carry != 0:
res = ListNode(carry)
res.next = cur
return res
return cur
def addTwoNum(self, l1, l2):
ans = ListNode(0)
if not l1:
return l2
if not l2:
return l1
val = l1.val + l2.val
ans = ListNode(val % 10)
ans.next = self.addTwoNum(l1.next, l2.next)
if val >= 10:
ans.next = self.addTwoNum(ListNode(1), ans.next)
return ans
def swapPairs(self, head: ListNode) -> ListNode:
if not head or not head.next:
return head
cur = head.next
head.next = self.swapPairs(cur.next)
cur.next = head
return cur
def Mundane(self, head):
ans = ListNode(-1)
ans.next = head
pre = ans
cur = ans.next
while cur and cur.next:
tmp = cur.next
pre.next = tmp
cur.next = tmp.next
tmp.next = cur
pre = cur
cur = cur.next
return ans.next