1290_Convert Binary Number in a Linked List to Integer

/*   1290_Convert Binary Number in a Linked List to Integer
Runtime: 0 ms, faster than 100.00% of Java online submissions for Convert Binary Number in a Linked List to Integer.
Memory Usage: 37.1 MB, less than 58.46% of Java online submissions for Convert Binary Number in a Linked List to Integer.



 */
class Solution {
    public int getDecimalValue(ListNode head) {
    //Reversing the list
        ListNode prev=null;
        while(head.next!=null)
        { ListNode temp=head.next;
            head.next=prev;
            prev=head;
            head=temp;
            
        }
        head.next=prev;
        
        
    //List reversed
    // iterating and calculating value in decimal
        int decimal=0,itt=1; 
        while(head!=null)
        {
            decimal+=head.val*itt;
            itt*=2;
            head=head.next;
        }
        
        return decimal;
    }
}