题目描述
给出一个排好序的链表,删除链表中的所有重复出现的元素,只保留原链表中只出现一次的元素。
例如:
给出的链表为1->2->3->3->4->4->5, 返回1->2->5.
给出的链表为1->1->1->2->3, 返回2->3.
代码实现
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) {
* val = x;
* next = null;
* }
* }
*/
public class Solution {
public ListNode deleteDuplicates(ListNode head) {
if(head == null){return null;}
ListNode dummy = new ListNode(0);
ListNode pre = dummy;
ListNode cur = head;
ListNode real = dummy;
while(cur != null){
if((pre == dummy ||pre.val != cur.val)&&(cur.next == null ||cur.val != cur.next.val)){
real.next = cur;
real = cur;
}
pre = cur;
cur = cur.next;
pre.next = null;
}
return dummy.next;
}
}