剑指offer---删除链表中的重复元素

在一个排序的链表中，存在重复的结点，请删除该链表中重复的结点，重复的结点不保留，返回链表头指针。 例如，链表1->2->3->3->4->4->5 处理后为 1->2->5

解题思路：使用O(1)的覆盖的删除方式，进行覆盖式删除

java

/* public class ListNode {    int val;    ListNode next = null;    ListNode(int val) {        this.val = val;    }}*/public class Solution {    public ListNode deleteDuplication(ListNode pHead) {if (pHead == null || pHead.next == null) {            return pHead;        }        ListNode dummy = new ListNode(-1);        dummy.next = pHead;        ListNode prev = dummy;        ListNode curr = pHead;        while (curr != null && curr.next != null) {            if (curr.val == curr.next.val) {                int val = curr.val;                while (curr != null && curr.val == val) {                    curr = curr.next;                }                prev.next = curr;            } else {                prev = curr;                curr = curr.next;            }        }        return dummy.next;    }}