题解 | #链表的奇偶重排#

//分别取出奇数链表和偶数链表，将偶数链表放在奇数链表后边即可 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) {
       if (head == null || head.next == null) {
     return head;
       }
    

    // write code here

     ListNode oddPre = new ListNode(-1);                   
      ListNode odd = oddPre;
    
    
    ListNode evenPre = new ListNode(-2);
    ListNode even = evenPre;
     int i = 1;
    ListNode cur = head;
     while (cur != null) {
    
     if (i % 2 != 0) {
         odd.next = cur;
         odd = odd.next;
    
    
     } else {
         even.next = cur;
         even = even.next;
    
     }
     i++;
     ListNode oldCur = cur;
     cur = cur.next;
     oldCur.next = null;
    

    }

    odd.next = evenPre.next;

    return oddPre.next;

  } }