算法练习(14) - 奇偶链表

class Solution {
    public ListNode oddEvenList(ListNode head) {
        if(head == null){
            return head;
        }
        ListNode odd = head;
        ListNode evenHead = head.next;
        ListNode even = evenHead;

        while(odd.next != null && even.next != null){
            odd.next = even.next;
            odd = odd.next;

            even.next = odd.next;
            even = even.next;
        }
        odd.next = evenHead;
        return head;
    }
}