链表的奇偶重排

public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     * 
     * @param head ListNode类 
     * @return ListNode类
     */
    public ListNode oddEvenList (ListNode head) {
        // write code here
        if(head==null||head.next==null){
            return head;
        }
        ListNode odd=head, even=head.next, oddHead=odd, evenHead=even;
        while(even!=null&&even.next!=null){
            odd.next= even.next;
            odd=odd.next;
            even.next=odd.next;
            even = even.next;
        }
        odd.next=evenHead;
        return oddHead;
    }
}