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.

題意：給一個有序的鏈表，讓我們?nèi)サ糁貜?fù)的節(jié)點。

java代碼：

public ListNode deleteDuplicates(ListNode head) {
        ListNode h1 = head;
        while(h1 != null && h1.next != null){
            if (h1.val == h1.next.val) {
                h1.next = h1.next.next;
            }else {
                h1 = h1.next;
            }
        }
        return head;
    }