Big O week 3 day 5 p1

import java.io.*;
import java.util.* ;

/****************************************************************

    Following is the class structure of the Node class:

        class Node
        {
        public:
	        int data;
	        Node *next;
	        Node(int data)
	        {
		        this->data = data;
		        this->next = NULL;
	        }
        };

*****************************************************************/

public class Solution {
	public static Node getListAfterReverseOperation(Node head, int n, int b[]) {
		Node prev = head , tmp = head;
		for(int i = 0; i < n; i++){
			int lol = b[i];
            ArrayList<Integer> a = new ArrayList<>();
            while(lol-- > 0 && tmp != null){
                a.add(tmp.data);
                tmp = tmp.next;
            }
            Collections.reverse(a);
            for(int j : a){
                prev.data = j;
                prev = prev.next;
            }
        }
		return head;
	}
}