Reverse Linked List II java

 1 public static ListNode reverseBetween(ListNode head, int m, int n) {
 2         ListNode pre=head,current=head,mPre = new ListNode(0),mNode =  new ListNode(0),nNode =  new ListNode(0),temp;
 3         mPre.next=head;
 4         int i=1;
 5         while(i<=n)
 6         {
 7             if(i==m-1)
 8                 mPre=current;
 9             if(i==m)
10                 mNode=current;
11             if(i==n)
12                 nNode=current;
13             if(m<i&&i<=n)
14             {
15                 temp=current;
16                 current=current.next;
17                 temp.next=pre;
18                 pre=temp;
19             }
20             else{
21                 pre=current;
22                 current=current.next;
23             }
24             i++;
25         }
26         mPre.next=nNode;
27         mNode.next=current;
28         if(m==1)
29             return nNode;
30         else
31         return head;
32             
33         }