Remove Duplicates from Sorted List @LeetCode

/**
 * 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.
 */
public class S83 {

	public static void main(String[] args) {
		ListNode n1 = new ListNode(1);
		ListNode n2 = new ListNode(1);
		n1.next = n2;
		ListNode n3 = new ListNode(2);
		n2.next = n3;
		
		ListNode x = deleteDuplicates(n1);
		x.print();
	}

	public static ListNode deleteDuplicates(ListNode head) {
		ListNode base = head;  // base 为每次被比较的对象
		if(head==null || head.next == null){
			return head;
		}
		ListNode cur = head.next;		// cur为每次去比较的对象
		
        while(base!=null && cur!=null){
        	if(base.val == cur.val){		// 重复了就跳过去
        		base.next = cur.next;
        	}else{		// 不重复就更新base
        		base = base.next;
        	}
        	cur = cur.next;	// 更新cur
        }
        
        return head;
    }
}