83. Remove Duplicates from Sorted List - Easy
Given a sorted linked list, delete all duplicates such that each element appear only once.
Example 1:
Input: 1->1->2 Output: 1->2
Example 2:
Input: 1->1->2->3->3 Output: 1->2->3
time: O(n), space: O(1)
/** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { val = x; } * } */ class Solution { public ListNode deleteDuplicates(ListNode head) { if(head == null || head.next == null) { return head; } ListNode cur = head; while(cur != null && cur.next != null) { if(cur.val == cur.next.val) { cur.next = cur.next.next; } else { cur = cur.next; } } return head; } }