public static void main(String args[]) {
double_ll<Integer> dll = new double_ll<Integer>(10);
dll.insert(20);
dll.insert(30);
dll.insert(40);
dll.print();
dll = reverse_dll(dll);
dll.print();
}
public static double_ll reverse_dll(double_ll dll) {
if (dll.isEmpty()) {
System.out.println("empty lst");
return null;
}
dll_node prev = null;
dll_node curr = dll.head;
while (curr != null) {
curr.prev = curr.next;
curr.next = prev;
prev = curr;
curr = curr.prev;
}
if (prev != null) {
dll.head = prev;
}
return dll;
}