Given a sorted linked list, delete all duplicates such that each element appear only once. See it on Leetcode
Given "1->1->2", return"1->2".
Given "1->1->2->3->3", return"1->2->3".
This is a simple problem that merely tests your ability to manipulate list node pointers. Because the input list is sorted, we can determine if a node is a duplicate by comparing its value to the node after it in the list. If it is a duplicate, we change the next pointer of the current node so that it skips the next node and points directly to the one after the next node.