Remove Duplicates from Sorted List

Link: http://oj.leetcode.com/problems/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.

 

/**
 * 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;
        ListNode p1 = head;
        ListNode p2 = head;
        ListNode result = new ListNode(0);
        ListNode result_point = result;
        while(p2!=null){
            while(p2!=null&&p2.val==p1.val)
            {
                p2 = p2.next;
            }
            result.next = p1;
            result = result.next;
            p1 = p2;
        }
        result.next = null;
        return result_point.next; 
    }
}