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.

解题的时候注意元素重复次数可能超过一次，需要循环处理

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