3.

A Queue is designed to be deterministic with a fixed maximum length.

The struct of Queue is below: a currEvent and an array.

{currEvent, {[0: Ex], [1: Ex], [2: Ex], [3: Ex]}}

An example of Queue is below.

{E3, {[0: END], [1: E2], [2: END], [3: E1]}}

It means the current pending event is E3. The following events in order are E1 and E2.

The currEvent E3 points to [3: E1], where 3 is the index of the array and E1 means the next event E1.

Then, the next event E1 points to [1: E2], where 1 is the index of the array and E2 means the next event E2.

Then, the next event E2 points to [2: END], where 2 is the index of the array and END means the end, i.e. no more events.

When the Queue has no events, it has the following:

{END, {[0: END], [1: END], [2: END], [3: END]}}

(a) Assume in the system, the events happened in the following time order:

T0: no events in queue.

T1: E1 is added to the queue.

T2: E0 is added to the queue.

T3: E3 is added to the queue.

T4: E1 is popped from the queue.

T5: E2 is added to the queue.

Follow the style below, show the queues after the time points, T1, T2, T3, T4, T5.

Time	currEvent	[0: x]	[1: x]	[2: x]	[3: x]
T0	END	[0: END]	[1: END]	[2: END]	[3: END]
T1		[0: ]	[1: ]	[2: ]	[3: ]
T2		[0: ]	[1: ]	[2: ]	[3: ]
T3		[0: ]	[1: ]	[2: ]	[3: ]
T4		[0: ]	[1: ]	[2: ]	[3: ]
T5		[0: ]	[1: ]	[2: ]	[3: ]

(b) Write four functions:

1. void initializeQueue(Queue* que)

2. bool isEmpty(Queue* que)

3. uint8_t pop(Queue* que)

4. void append(Queue* que, unit8_t ev)