19. Remove Nth Node From End of List

class Solution {
public:
    ListNode* removeNthFromEnd(ListNode* head, int n) {
        ListNode* Head=new ListNode(-1);
        Head->next=head;
        
        ListNode* pre=Head,*cur=Head;
        int len=0;
        while(cur&&len<=n)
        {
            len++;
            cur=cur->next;
        }
        while(cur)
        {
            cur=cur->next;
            pre=pre->next;
        }
        pre->next=pre->next->next;
        head=Head->next;
        delete Head;
        return head;
    }
};