328. Odd Even Linked List

/**
* Definition for singly-linked list.
* public class ListNode {
*     int val;
*     ListNode next;
*     ListNode(int x) { val = x; }
* }
*/
public class Solution {
public ListNode oddEvenList(ListNode head) {
if(head==null){
return head;
}
ListNode odd;
ListNode even;
ListNode oddtmp;
ListNode eventmp;
odd=head;//奇数头
even=head.next;//偶数的头部
oddtmp=odd;
eventmp=even;
while(oddtmp.next!=null&&eventmp.next!=null){
oddtmp.next=eventmp.next;
oddtmp=oddtmp.next;
eventmp.next=oddtmp.next;
eventmp=eventmp.next;
}
oddtmp.next=even;
return odd;
}
}