Remove Duplicates from Sorted List II

Medium

Given the head of a sorted linked list, delete all nodes that have duplicate values, leaving only values that appear exactly once. Return the sorted list.

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

• 0 <= number of nodes <= 300
• -100 <= Node.val <= 100
• The list is sorted in non-decreasing order.