链表两两交换节点：C++ 代码实现及优化

#include"ListNode.hpp"

class Solution { public: ListNode* swapPairs(ListNode* head) { if (head == nullptr || head->next == nullptr) { return head; } ListNode* newHead = head->next; ListNode* prev = nullptr; ListNode* curr = head;

        while (curr != nullptr && curr->next != nullptr) {
            ListNode* next = curr->next;
            curr->next = next->next;
            next->next = curr;
            
            if (prev != nullptr) {
                prev->next = next;
            }
            
            prev = curr;
            curr = curr->next;
        }
        
        return newHead;
    }

};