反转链表

题目描述

输入一个链表，反转链表后，输出新链表的表头。

/*
struct ListNode {
	int val;
	struct ListNode *next;
	ListNode(int x) :
			val(x), next(NULL) {
	}
};*/
class Solution {
public:
    ListNode* ReverseList(ListNode* pHead) {
        ListNode *head = (ListNode*)malloc(sizeof(ListNode));
        head->next = NULL;
        
        while(pHead)
        {
            ListNode *flag = (ListNode*)malloc(sizeof(ListNode));
            flag->val = pHead->val;
            
            flag->next = head->next;
            head->next = flag;
            
            pHead = pHead->next;           
        }
        
        return head->next;
    }
};