题目

方法

遍历一遍Linked List，将相同的元素删除，即可。

	    public ListNode deleteDuplicates(ListNode head) {
	        ListNode first = head;
	        ListNode second;
	        while(first != null){
	            second = first.next;
	            if((second != null) && (second.val == first.val)){
	                first.next = second.next;
	            }else{
	                first = second;
	            }
	        }
	        return head;
	    }