Remove Duplicates from Sorted List.java

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.

/**
 * 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) return head;
        int cur = head.val;
        ListNode p = head.next;
        ListNode prev = head;
        while (p != null) {
            if (p.val == cur) {
                prev.next = p.next;
        	p = prev.next;
            } else {
        	cur = p.val;
        	prev = prev.next;
        	p = p.next;
            }
        }
        return head;
    }
}