Reverse linked list

reverselist.java

public ListNode reverseList(ListNode head) {
    // Add your code below this line. Do not modify any other code.            

    ListNode currentNode = head;
    ListNode previousNode= null;
    
    while(currentNode != null)
    {
        ListNode nextNode = currentNode.next;
        currentNode.next = previousNode;
        previousNode = currentNode;
        currentNode = nextNode;
    }
    
    return previousNode;

    // Add your code above this line. Do not modify any other code.
}