Title description
Given a sorted linked list, delete all repetitive elements in the linked list, and keep only the elements that appear only once in the original linked list.
For example: the
given list is 1-> 2-> 3-> 3-> 4-> 4-> 5, return 1-> 2-> 5. The
given list is 1-> 1-> 1-> 2-> 3, return 2-> 3.
Code
/**
* 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;
}
}