def splitListToParts(self, head: Optional[ListNode],
k: int) -> List[Optional[ListNode]]:
ans: List[ListNode] = []
cur = head
allcount = 0
while cur:
allcount += 1
cur = cur.next
eachcount = allcount // k
remainder = allcount - eachcount * k
cur = ListNode(0)
cur.next = head
for i in range(k):
if eachcount + remainder == 0:
ans.append(None)
else:
tmp = eachcount
while cur.next and tmp > 0:
cur = cur.next
tmp -= 1
if remainder > 0:
if cur.next:
cur = cur.next
remainder -= 1
temp = cur.next
cur.next = None
ans.append(head)
head = temp
cur = ListNode(0)
cur.next = head # ensure cur is the tail element
return ans
def mergeList(l1: ListNode, l2: ListNode) -> ListNode:
tmp = ListNode(0)
sortlist = tmp
while l1 and l2:
if l1.val < l2.val:
tmp.next = l1
l1 = l1.next
tmp = tmp.next
else:
tmp.next = l2
l2 = l2.next
tmp = tmp.next
if l1:
tmp.next = l1
elif l2:
tmp.next = l2
return sortlist.next
def reverseKGroup(self, head: ListNode, k: int) -> ListNode:
count = 0
ltmp: ListNode = head
while count < k and ltmp:
ltmp = ltmp.next
count += 1
if count < k:
return head
cur: ListNode = self.reverseKGroup(ltmp, k)
while count > 0:
ltmp = head.next
head.next = cur
cur = head
head = ltmp
count -= 1
return cur
