题解 | 反转链表

/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 * };
 */
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param head ListNode类 
 * @return ListNode类
 */
struct ListNode* ReverseList(struct ListNode* head ) {
    // write code here
    struct ListNode* n1 = NULL;
    struct ListNode* n2 = head;
    struct ListNode* n3 =head->next;
    while(n2)
    {
        n2->next = n1;
        n1 =n2;
        n2 = n3;
        if(n3)
        {
            n3 = n3->next;
        }

        
    }
    return n1;
}