leetcode remove nth node from end of list

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode* removeNthFromEnd(ListNode* head, int n) {
        ListNode* dummy = new ListNode(0);
        dummy->next = head;
        ListNode* fast = dummy;
        ListNode* normal = dummy;
        for(int i = 0; i < n; ++i) {
            fast = fast->next;
        }
        while(fast->next != NULL) {
            fast = fast->next;
            normal = normal->next;
        }
        ListNode *tmp = normal->next;
        normal->next = normal->next->next;
        delete(tmp);
        return dummy->next;
    }
};