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) {
        int f = 1;
        ListNode odd = new ListNode(0);
        ListNode even = new ListNode(0);
        ListNode p_o = odd;
        ListNode p_e = even;
        while(head!=null){
            if(f%2==0){
                ListNode node = new ListNode(head.val);
                p_e.next = node;
                p_e = p_e.next;
            }
            else{
                ListNode node = new ListNode(head.val);
                p_o.next = node;
                p_o = p_o.next;
            }
            head=head.next;
            f++;
        }
        p_o.next = even.next;
        p_e.next = null;
        return odd.next;
    }
}