slow = slow.next
fast = fast.next.next
ReverseHead = self.__reverse(slow.next)
slow.next = None
ptr1 = head
ptr2 = ReverseHead
while ptr1 and ptr2:
tmp1 = ptr1.next
tmp2 = ptr2.next
ptr1.next = ptr2
ptr2.next = tmp1
ptr1 = tmp1
ptr2 = tmp2
def __reverse(self, head: ListNode) -> ListNode:
dummy = ListNode(0)
dummy.next = head
ptr = head
while ptr and ptr.next:
tmp = ptr.next
ptr.next = tmp.next
tmp.next = dummy.next
dummy.next = tmp
return dummy.next
str = "12345"
head = createList(str)
sol = Solution()
sol.reorderList(head)
print("123")
kPointer.next = kPointer.next.next
return head
def move_middle_to_head(head):
prev = None
slow = head
fast = head.next if head else None
if not fast or not slow:
return head
while (fast):
prev = slow
slow = slow.next
fast = fast.next.next if fast.next else fast.next
prev.next = slow.next
slow.next = head
return slow
arr1 = [[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15], [1], [1, 2],
[1, 2, 3], [], [1, 2, 3, 4, 5, 6], [1, 2, 3, 4, 5, 6, 7]]
for arr in arr1:
head = createList(arr)
head = move_middle_to_head(head)
print(extractList(head))