Given the head of a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list. Return the linked list sorted as well.
Example 1:
Input: head = [1,2,3,3,4,4,5] Output: [1,2,5]
Example 2:
Input: head = [1,1,1,2,3] Output: [2,3]
Constraints:
The number of nodes in the list is in the range [0, 300].
-100 <= Node.val <= 100
The list is guaranteed to be **sorted** in ascending order.
- code
class Solution:
def deleteDuplicates(self, head: Optional[ListNode]) -> Optional[ListNode]:
res = pointer = ListNode(-101, head)
move = head
while move and move.next:
if pointer.val != move.val and move.val != move.next.val:
pointer.next = move
pointer = pointer.next
else:
while move.next and move.next.val == move.val:
move = move.next
move = move.next
pointer.next = move
return res.next