Reverse Linkedlist

class Solution {
public:
    ListNode* reverseList(ListNode* head) {
        ListNode* prev = NULL;
        ListNode* curr = head;
        ListNode* next;

        while(curr!=NULL){
            next = curr->next;
            curr->next = prev;
            prev= curr;
            curr = next;
        }

        return prev;
    }
};