"Sword finger offer" linked list inversion

Title Description

Enter a linked list , After reversing the list , Output the header of the new linked list .

The first interpolation ： 

/*
struct ListNode {
	int val;
	struct ListNode *next;
	ListNode(int x) :
			val(x), next(NULL) {
	}
};*/
class Solution {
public:
    ListNode* ReverseList(ListNode* pHead) {
		ListNode *new_next = NULL;
		ListNode *now;
		while (pHead != NULL){
			now = pHead;
			pHead = pHead->next;

			now->next = new_next;
			new_next = now;
		}
		return new_next;
	}
};