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) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        auto dummy = new ListNode(-1);
        dummy->next = head;
        auto prev = dummy, cur = dummy;
        for (int i=0; i<n; ++i)
            cur = cur->next;
        while (cur->next)
        {
            cur = cur->next;
            prev = prev->next;
        }
        cur = prev->next;
        prev->next = cur->next;
        delete cur;
        cur = dummy->next;
        delete dummy;
        return cur;
    }
};