反转链表

题目描述

思路

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

return last;
}
};