5652. 交换链表中的节点
状态:AC
代码:
/**
* 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* swapNodes(ListNode* head, int k) {
int i = 1;
ListNode* pre = head;
ListNode* back = head;
while(i++<k){
pre = pre->next;
}
ListNode* tmp = pre;
while(tmp->next){
tmp = tmp->next;
back = back->next;
}
swap(pre->val,back->val);
return head;
}
};