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) {
       ListNode osNode = null;
        ListNode jsNode = head;
        ListNode temp = null;
        ListNode tempNext = null;
        List<Integer> jsList = new ArrayList<>();
        if (head != null && head.next != null) {
            osNode = head.next;
        }else {
            return head;
        }
        while (jsNode != null) {
            jsList.add(jsNode.val);
            if (jsNode.next != null) {
                jsNode = jsNode.next.next;
            } else {
                jsNode = null;
            }
        }
        ListNode osNodeTemp = osNode;
        while (osNodeTemp != null) {
            if (osNodeTemp.next != null) {
                osNodeTemp.next = osNodeTemp.next.next;
                osNodeTemp = osNodeTemp.next;
            } else {
                osNodeTemp.next = null;
                break;
            }
        }
        for (int i = 0; i < jsList.size(); i++) {
            if (i == 0) {
                temp = new ListNode(jsList.get(i));
                tempNext = temp;
            } else {
                tempNext.next = new ListNode(jsList.get(i));
                tempNext = tempNext.next;
            }
            if (i == jsList.size() - 1) {
                tempNext.next = osNode;
            }
        }
        return temp;
    }
       
}