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
        if(head == null) return null;
        ListNode list1 = head;
        ListNode list2 = head.next;
        ListNode odd =list1;
        ListNode event = list2;

        while(event!=null&&event.next!=null){
            odd.next = odd.next.next;
            odd = odd.next;
            event.next = event.next.next;
            event = event.next;
        }
        
        odd.next = list2;
        
        return list1;
    }
}