4. Write the equivalent infix expressions for the following postfix expressions:

x y + z * w -

x y * z / w +

x y z + * w -

5. Explain why, in the linked implementation of a stack, it is not necessary to implement the operation to determine wether the stack is full.

6. Suppose that stack isn an object of type linkedStackType . What is the difference between the statements stack.top(); and stack.pop();?

7. Suppose that queue is a queueType object and the size of the array implement queue is 100. What are the values of queueFront and queueRear after adding an element to queue if:

queueFront = 50 and queueRear = 99

queueFront = 99 and queueRear = 25

queueFront = 25 and queueRear = 75

8. Suppose that queue is a queueType object and the size of the array implement queue is 100. What are the values of queueFront and queueRear after removing an element from queue if:

queueFront = 50 and queueRear = 99

queueFront = 99 and queueRear = 25

queueFront = 25 and queueRear = 75