Three operations possible in a quack is QUACKPUSH, QUACKPOP and QUACKPULL.
Explanation:
A quack is a data structure combining properties of both stacks and queues. It can be viewed as a list of elements written left to right such that three operations are possible, these include:
QUACKPUSH(x): add a new item x to the left end of the list; QUACKPOP(): remove and return the item on the left end of the list; QUACKPULL(): remove the item on the right end of the list.Elements in the quack are stored in stacks. The component stacks can be accessed only through the standard stack functions PUSH and POP.