문제 설명 문제 Given the head of a sorted linked list, delete all duplicates such that each element appears only once. Return the linked list sorted as well. 입출력 예시 Input: head = [1,1,2] Output: [1,2] Input: head = [1,1,2,3,3] Output: [1,2,3] 제한사항 The number of nodes in the list is in the range [0, 300]. -100