一、题目内容

二、题解

解法1：

思路

cur!=null&&cur.next!=null 可能cur是链表最后一个元素

代码

public class Solution {
    public ListNode oddEvenList (ListNode head) {
        // write code here
        if(head == null){
            return null;
        }
        ListNode newHead = new ListNode(-1);
        ListNode dummy = newHead;
        ListNode cur = head;
        while(cur!=null&&cur.next!=null){
            newHead.next = new ListNode(cur.val);
            cur = cur.next.next;
            newHead = newHead.next;
        }
        if(cur!=null){
            newHead.next = new ListNode(cur.val);
            newHead = newHead.next;
        }
        cur = head.next;
        while(cur!=null&&cur.next!=null){
            newHead.next = new ListNode(cur.val);
            cur = cur.next.next;
            newHead = newHead.next;
        }
        if(cur!=null){
            newHead.next = new ListNode(cur.val);
            newHead = newHead.next;
        }
        return dummy.next;
    }
}