public class RemoveNode {
	public class Node{
		public int value;
		public Node next;
		public Node(int data){
			value=data;
		}
	}
public Node removeMidNode(Node head){
	if(head==null||head.next==null){
		return head;
	}
	if(head.next.next==null){
		return head.next;
	}
	Node pre=head;
	Node cur=head.next.next;
	while(cur.next!=null&&cur.next.next!=null){
		pre=pre.next;
		cur=cur.next.next;
	}
	pre.next=pre.next.next;
	return head;
}
public Node removeByRatio(Node head,int a,int b){
	if(a<1||a>b){
		return head;
	}
	int n=0;
	Node cur=head;
	while(cur!=null){
		n++;
		cur=cur.next;
	}
	n=(int)Math.ceil(((double)(a*n))/(double)b);
	if(n>1){
		cur=head;
		while(--n!=1){
			cur=cur.next;
		}
		cur.next=cur.next.next;
	}
	return head;
}
}