Examine the following declarations and definitions for the array-based implementations for the stack and queue adts. assume that exception class pushonfullstack and class poponemptystack have been defined and are available. read the following code segment and fill in blank #6.

class stacktype
{

public:

stacktype();

void push(stackitemtype item);

void pop();

private:

int top;

itemtype items[max_stack];

};

void stacktype: : stacktype()

{

top = -1;

}

void stacktype: : push(itemtype item)

{

// 1

; // 2

; // 3

; // 4

}

class quetype

{

public:

// prototypes of quetype operations

// go here

private:

int front;

int rear;

itemtype items[max_queue];

}

void quetype: : quetype()

{

front = max_queue - 1;

rear = max_queue - 1;

}

boolean quetype: : isempty()

{

return (rear == front);

}

void quetype: : enqueue(itemtype item)

{

; // 5

; // 6

}

[1] rear = (rear +1) % max_queue
[2] items[rear] = item
[3] rear = (rear % max_queue) + 1
[4] items[front] = item