19. Remove Nth Node From End of List

class Solution {
    public ListNode removeNthFromEnd(ListNode head, int n) {
        if(head.next == null) return null;

        int i = 1;
        ListNode curr = Reverce(head),c = head;
        head = curr;
        if(n == 1) { head = curr = curr.next;}
        else{
                while(curr != null){
                    
                    if(i+1 == n){
                        if(curr.next == null) curr.next = curr.next;
                        else curr.next = curr.next.next;
                        break;
                    }
                    curr = curr.next;
                    i++;
                }
        }
        return Reverce(head);
    }
    public ListNode Reverce(ListNode head){
        ListNode pre = null, nexto, c;
        while(head != null){
            nexto = head.next;
            head.next = pre;
            pre = head;
            head = nexto;
        }        
        return pre;
    }
}