Remove Duplicates from Sorted List II
Given the head of a sorted linked list, delete all nodes that have duplicate values, leaving only nodes with distinct values from the original list.
Because the linked list is sorted, duplicate values appear consecutively. Return the linked list sorted as well.
Example 1
[1] -> [2] -> [3] -> [3] -> [4] -> [4] -> [5] -> null --- [1] -> [2] -> [5] -> null
Input
head = [1,2,3,3,4,4,5]Output
[1,2,5]The values 3 and 4 appear more than once, so all nodes with those values are removed.
Example 2
[1] -> [1] -> [1] -> [2] -> [3] -> null --- [2] -> [3] -> null
Input
head = [1,1,1,2,3]Output
[2,3]The value 1 appears more than once, so all nodes with value 1 are removed.
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.