链表反转 C++ 版本 leetcode206

(原题网址)[https://leetcode.com/problems/reverse-linked-list/description/]

给出我的解答

#include <iostream>

using namespace std;

//Definition for singly-linked list.
struct ListNode {
    int val;
    ListNode *next;
    explicit ListNode(int x) : val(x), next(nullptr) {}
};



class Solution {
public:
    ListNode* reverseList(ListNode* head) {
        if (head == nullptr){
            return head;
        }
        else if(head->next == nullptr){
            return head;
        }
        ListNode* prev = nullptr;
        ListNode* curr;
        while(head != nullptr){
            curr = head;
            head = head->next;
            curr->next = prev;
            prev = curr;
        }
        return prev;
    }
};

并附上测试代码：

int main() {
    std::cout << "Hello, World!" << std::endl;
    ListNode n1(0);
    ListNode n2(2);
    ListNode n3(5);
    ListNode n4(7);
    ListNode n5(10);
    n1.next = &n2;
    n2.next = &n3;
    n3.next = &n4;
    n4.next = &n5;
//    遍历一个链表
    ListNode* head = &n1;
    while(head){
        cout << head->val << ' ';
        head = head->next;
    }

    Solution so;
    so.reverseList(&n1);
    cout << endl;

    head = &n5;
    while(head){
        cout << head->val << ' ';
        head = head->next;
    }

    return 0;
}