leetcode链接:24. 两两交换链表中的节点 - 力扣(LeetCode)
            
            
              cpp
              
              
            
          
          struct ListNode * swapPairs(struct ListNode * head)
{
        typedef struct ListNode ListNode;
        
        ListNode *fakehead = (ListNode *)malloc(sizeof(ListNode));
        fakehead->next = head;
        ListNode* right = fakehead->next;
        ListNode *left = fakehead;
        while(left && right && right->next)
        {
            left->next = right->next;
            right->next = left->next->next;
            left->next->next = right;
            left = right;
            right = left->next;
        }
            return fakehead->next;
}