asap please

6. Suppose you want to implement a Stack and you are going to use a List as the underlying data structure. a. How can you achieve 0(1) for push? b. How can you achieve O(1) for pop? 7. Suppose you want to implement a Queue and you are going to use a Linked List as the underlying data structure. a. How can you achieve O(1) for queue? b. How can you achieve O(1) for dequeue