题解 | #牛牛的链表交换#

#include <iostream>
#include <regex>
using namespace std;

struct Node
{
    int val;
    Node* next;
    Node(): val(0), next(nullptr) {}
    Node(int val): val(val), next(nullptr) {}
    Node(int val, Node* next): val(val), next(next) {}
} ;

void changeNode(Node* dummy, int ind)
{
    
    Node* node1Pre = dummy;
    int i = 0;
    while (node1Pre != nullptr && i != ind - 1)
    {
        node1Pre = node1Pre->next;
        ++i;
    }
    Node* node1 = node1Pre->next; 
    Node* node2 = node1->next;
    node1Pre->next = node2;
    Node* temp = node2->next;
    node2->next = node1;
    node1->next = temp;
}
int main() {
    int n;
    cin >> n;
    int i = 0;
    Node* dummy = new Node();
    Node* node = dummy;
    while (i != n)
    {
        int d;
        cin >> d;
        node->next = new Node(d);
        node = node->next;
        i++;
    }
    changeNode(dummy, 1);
    changeNode(dummy, n - 1);
    node = dummy->next;
    while (node != nullptr)
    {
        cout << node->val << " ";
        node = node->next;
    }
    
    return 0;
    

}
// 64 位输出请用 printf("%lld")

按照题解模拟就可以了