给定一个已排序的链表的头head,删除所有重复的元素,使每个元素只出现一次.返回已排序的链表
emmmm,太简单了,不知道说什么
public static ListNode deleteDuplicates(ListNode head) {
if(head==null || head.next==null) return head;
ListNode left = head,right = head.next;
while(right!=null){
while(right!=null && left.val==right.val){
right=right.next;
}
left.next = right;
left = right;
}
return head;
}