题解 | #链表的奇偶重排#

import java.util.*;

/*
 * public class ListNode {
 *   int val;
 *   ListNode next = null;
 *   public ListNode(int val) {
 *     this.val = val;
 *   }
 * }
 */

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
        List<Integer> list=new ArrayList<>();
        ListNode cur=head;
        int pos=1;
        while(cur!=null){
            if(pos%2==1){
                list.add(cur.val);
            }
            cur=cur.next;
            pos=pos+1;
        }
        pos=1;
        cur=head;
        while(cur!=null){
            if(pos%2==0){
                list.add(cur.val);
            }
            cur=cur.next;
            pos++;
        }
        cur=head;
        int i=0;
        while(cur!=null){
            cur.val=list.get(i++);
            cur=cur.next;
        }
        return head;
    }
}