19. Remove Nth Node From End of List
class Solution {
public ListNode removeNthFromEnd(ListNode head, int n) {
ListNode dumy=new ListNode(0);
dumy.next=head;
ListNode p1=dumy,p2=dumy;
for(int i=0;p1!=null;i++){
p1=p1.next;
if(i>n){
p2=p2.next;
}
}
p2.next=p2.next.next;
return dumy.next;
}
}