def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode:
dummyHead = ListNode(-1)
cur = dummyHead
x = 0
while l1 or l2:
sumTmp = None
if l1 and l2:
sumTmp = l1.val + l2.val + x
l1, l2 = l1.next, l2.next
elif l1 is None:
sumTmp = l2.val + x
l2 = l2.next
else:
sumTmp = l1.val + x
l1 = l1.next
if sumTmp >= 10:
x = 1
sumTmp = sumTmp % 10
else:
x = 0
node = ListNode(sumTmp)
cur.next = node
cur = cur.next
if x == 1:
node = ListNode(1)
cur.next = node
return dummyHead.next
def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode:
dummyHead = ListNode(-1)
stack1 = list()
stack2 = list()
while l1:
stack1.append(l1.val)
l1 = l1.next
while l2:
stack2.append(l2.val)
l2 = l2.next
x = 0
while stack1 or stack2:
sumTmp = None
if stack1 and stack2:
sumTmp = stack1.pop() + stack2.pop() + x
elif stack2:
sumTmp = stack2.pop() + x
else:
sumTmp = stack1.pop() + x
if sumTmp >= 10:
sumTmp = sumTmp % 10
x = 1
else:
x = 0
node = ListNode(sumTmp)
node.next = dummyHead.next
dummyHead.next = node
if x == 1:
node = ListNode(1)
node.next = dummyHead.next
dummyHead.next = node
return dummyHead.next
def removeElements(self, head: ListNode, val: int) -> ListNode:
dummyHead = ListNode(-1)
dummyHead.next = head
pre, cur = dummyHead, head
while cur:
if cur.val == val:
pre.next = cur.next
else:
pre = cur
cur = cur.next
return dummyHead.next
def reverseKGroup(self, head: ListNode, k: int) -> ListNode:
dummyHead = ListNode(-1)
dummyHead.next = head
pre = dummyHead
for i in range(1, k):
pre = pre.next
cur = pre.next
next = cur.next
pre.next = next
dummyHead.next = cur
cur.next = head
return dummyHead.next
def mergeKLists(self, lists: List[ListNode]) -> ListNode:
pq = queue.PriorityQueue()
for link in lists:
while link:
pq.put(link.val)
link = link.next
dummyHead = ListNode(-1)
cur = dummyHead
while not pq.empty():
node = ListNode(pq.get())
cur.next = node
cur = cur.next
return dummyHead.next
def removeNthFromEnd(self, head: ListNode, n: int) -> ListNode:
dummyHead = ListNode(-1)
dummyHead.next = head
p = dummyHead #要删除节点的前一个索引位置
q = dummyHead
for _ in range(n + 1):
q = q.next
while q:
p = p.next
q = q.next
delNode = p.next
nextNode = delNode.next
p.next = nextNode
return dummyHead.next
def removeNthFromEnd(self, head: ListNode, n: int) -> ListNode:
dummyHead = ListNode(-1)
dummyHead.next = head
pre = dummyHead
while pre:
test = pre
for i in range(n + 1):
test = test.next
if test is None:
break
pre = pre.next
delNode = pre.next
nextNode = delNode.next
pre.next = nextNode
return dummyHead.next
def partition(self, head: ListNode, x: int) -> ListNode:
lDummyHead = ListNode(-1)
rDummyHead = ListNode(-1)
lCur = lDummyHead
rCur = rDummyHead
while head:
val = head.val
node = ListNode(val)
if val < x:
lCur.next = node
lCur = lCur.next
else:
rCur.next = node
rCur = rCur.next
head = head.next
lCur.next = rDummyHead.next
return lDummyHead.next
def oddEvenList(self, head: ListNode) -> ListNode:
lDummyHead = ListNode(-1)
rDummyHead = ListNode(-1)
lCur = lDummyHead
rCur = rDummyHead
i = 1
while head:
node = ListNode(head.val)
if i % 2 == 1:
lCur.next = node
lCur = lCur.next
else:
rCur.next = node
rCur = rCur.next
head = head.next
i += 1
lCur.next = rDummyHead.next
return lDummyHead.next
def rotateRight(self, head: ListNode, k: int) -> ListNode:
if not head or not head.next:
return head
dummyHead = ListNode(-1)
dummyHead.next = head
countCur = dummyHead.next
count = 0
while countCur:
countCur = countCur.next
count += 1
for _ in range(k % count): # 解决非必要的旋转
p = dummyHead
q = dummyHead.next
while q.next:
p = p.next # 指向倒数第2个节点
q = q.next # 指向最后一个node
q.next = dummyHead.next
dummyHead.next = q
p.next = None
return dummyHead.next
def reverseList(self, head: ListNode) -> ListNode:
dummyHead = ListNode(-1)
while head:
node = ListNode(head.val)
node.next = dummyHead.next
dummyHead.next = node
head = head.next
return dummyHead.next