algorithm/Week_01/id_126/LeetCode_24_126.java at master · feixiangcode/algorithm · GitHub

27 lines (24 loc) · 626 Bytes

/**

* Definition for singly-linked list.

* public class ListNode {

* int val;

* ListNode next;

* ListNode(int x) { val = x; }

* }

class Solution {

public ListNode swapPairs(ListNode head) {

//判断当前值和下一个值是否为空

//不为空交换

//为空不动

if(head==null||head.next==null){

return head;

}

ListNode listNode=new ListNode(0);

listNode.val=head.val;

listNode.next=swapPairs(head.next.next);

head=head.next;

head.next=listNode;

return head;

}

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