删除链表中重复的结点

题目描述

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
/*
public class ListNode {
int val;
ListNode next = null;

ListNode(int val) {
this.val = val;
}
}
*/
public class Solution {
ListNode deleteDuplication(ListNode pHead)
{
if(pHead==null) return null;
ListNode p = pHead;
ListNode n = new ListNode(0);
ListNode pre = n;
n.next = pHead;
boolean flag = false;
while(p!=null){
ListNode q = p.next;
if(q==null) break;
if(q.val==p.val){
while(q!=null && q.val==p.val){
q = q.next;
}
pre.next = q;
p =q;
}else{
if(!flag){
n.next = p;
flag = true;
}
pre = p;
p = q;
}
}
return n.next;
}
}