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
        int i = 1;
        ListNode p = head;
        ListNode oddHead = new ListNode(0);
        ListNode oddEnd = oddHead;
        ListNode evenHead = new ListNode(0);
        ListNode evenEnd = evenHead;
        while (p != null) {
            if (i % 2 == 0) {
                evenEnd.next = p;
                evenEnd = evenEnd.next;
            } else {
                oddEnd.next = p;
                oddEnd = oddEnd.next;
            }
            i++;
            p = p.next;
        }
        evenEnd.next = null;
        oddEnd.next = evenHead.next;
        return oddHead.next;
    }
}