Leetcode - Remove Duplicates from Sorted List

Remove Duplicates from Sorted List

 

Given a sorted linked list, delete all duplicates such that each element appear only once.
For example,
Given 1->1->2, return 1->2.
Given 1->1->2->3->3, return 1->2->3.

Solution:

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) {
 *         val = x;
 *         next = null;
 *     }
 * }
 */
public class Solution {
    public ListNode deleteDuplicates(ListNode head) {
        if(head == null || head.next == null)   return head;
        
        ListNode node = head;
        
        while(node != null) {
            ListNode tmp = node.next;
            while(tmp != null && node.val == tmp.val) {
                tmp = tmp.next;
            }
            node.next = tmp;
            node = node.next;
        }
        
        return head;
    }
}