【C++】两两交换链表中的节点

#include <iostream>
#include <stack>
using namespace std;
struct ListNode {
  int val;
  ListNode* next;
  ListNode(int x) :val(x), next(nullptr) {}
};
ListNode* swapPairs1(ListNode* head) {
  ListNode* dummyHead = new ListNode(0);
  dummyHead->next = head;//使用虚拟头节点指向head
  ListNode* cur = dummyHead;
  while (cur->next && cur->next->next) {
    ListNode* tmp = cur->next;
    ListNode* tmp1 = cur->next->next->next;
    cur->next = cur->next->next;
    cur->next->next = tmp;
    tmp->next = tmp1;
    cur = cur->next->next;
  }
  return dummyHead->next;
}
int main() {
  ListNode* head = new ListNode(1);
  head->next = new ListNode(2);
  head->next->next = new ListNode(4);
  head->next->next->next = new ListNode(8);

  ListNode* swapList = swapPairs1(head);
  std::cout << "Merged List: ";
  printList(swapList);
  // 释放内存  
  ListNode* current = swapList;
  while (current) {
    ListNode* next = current->next;
    delete current;
    current = next;
  }

  return 0;
}