题解 | #反转链表#

/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 * };
 */

/**
 * 
 * @param pHead ListNode类 
 * @return ListNode类
 */
struct ListNode* ReverseList(struct ListNode* pHead ) {
    // write code here
    struct ListNode* Head2, *ptr, *temp, *fptr;
    if(pHead == NULL)
    {
        return NULL;
    }
    else if(!pHead->next)
    {
        return pHead;
    }
    else
    {
        fptr = pHead;
        ptr = pHead->next;
        pHead->next = NULL;
        while(ptr->next)
        {
            temp = ptr->next;
            ptr->next = fptr;
            fptr = ptr;
            ptr = temp;
        }
        ptr->next = fptr;

        return ptr;
    }

}