Remove Duplicates from Sorted List

描述
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.

删除重复节点

代码

public static ListNode deleteDuplicates(ListNode head) {
        if (head == null || head.next == null) {
            return head;
        }
        ListNode ptr1 = head;
        ListNode ptr2 = head.next;
        while (ptr2 != null) {
            if (ptr1.data == ptr2.data) {
                ptr2 = ptr2.next;
                if (ptr2 == null)
                    ptr1.next = null;
            } else {
                ptr1.next = ptr2;// 衔接链表
                ptr1 = ptr1.next;// 各移到下一个节点
                ptr2 = ptr2.next;
            }
        }
        return head;
    }