https://leetcode.cn/problems/swap-nodes-in-pairs/
思路
画图模拟一下过程
code
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode() : val(0), next(nullptr) {}
* ListNode(int x) : val(x), next(nullptr) {}
* ListNode(int x, ListNode *next) : val(x), next(next) {}
* };
*/
class Solution {
public:
ListNode* swapPairs(ListNode* head) {
ListNode* dummyNode = new ListNode(0);
dummyNode->next = head;
ListNode* cur = dummyNode;
while(cur->next&&cur->next->next){
ListNode* tmp=cur->next; //记录临时节点
ListNode* tmp1=cur->next->next->next; //记录临时节点
cur->next =cur->next->next;
cur->next->next=tmp;
cur->next->next->next=tmp1;
cur=cur->next->next;
}
return dummyNode->next;
}
};