题解 | #反转链表#

/*
struct ListNode {
    int val;
    struct ListNode *next;
    ListNode(int x) :
            val(x), next(NULL) {
    }
};*/
class Solution {
public:
    ListNode* ReverseList(ListNode* pHead) {
        if (pHead == NULL) {
            return pHead;
        }
        ListNode *forword = pHead->next;
        ListNode *back = NULL;
        while(forword)
        {
            pHead->next = back;
            back = pHead;
            pHead = forword;
            forword = forword->next;
        }
        pHead->next = back;
        return pHead;
    }
};