C / C++ / MFC

#include<iostream.h><br />
class Queue<br />
{<br />
private:<br />
    int data[10];//maximum length of queue<br />
    int length;<br />
    int first;<br />
    int last;<br />
public:<br />
    Queue(int);<br />
    void push(int);<br />
    int pop();<br />
	void show();<br />
<br />
};<br />
// sets the size of the queue and both first and last to -1<br />
Queue::Queue(int len)<br />
{<br />
    length=len;<br />
    first=-1;<br />
    last=-1;<br />
}<br />
/* Function to pop (delete) the first student in the queue<br />
if the queue has any data in it*/<br />
int Queue::pop()<br />
{<br />
 int deleted;<br />
    if(first == -1) <br />
    {<br />
        return (0);<br />
    }<br />
    deleted=data[first]; <br />
    if(first==last)<br />
    {<br />
        first=-1;<br />
        last=-1;<br />
    }<br />
    else<br />
    first++;<br />
    return deleted;<br />
}<br />
<br />
/* Dispalys the menu allowing incorrect data entered<br />
to display an error message and re-show thr menu*/<br />
int menu()<br />
{<br />
    int choice = 0;<br />
    cout<<"\n\n\t\t**MAIN MENU**";<br />
    cout<<"\n\n\t1\tStudent number to join the queue";<br />
    cout<<"\n\t2\tStudent seen (Remove from queue)";<br />
    cout<<"\n\t3\tView the students in the queue";<br />
	cout<<"\n\t4\tEXIT";<br />
    cout<<"\n\n\tPlease enter your choice : ";<br />
    cin>>choice;<br />
    return choice;<br />
}<br />
/* Inserts the StudentID and shows message if <br />
the queue is full*/<br />
void Queue::push(int out)<br />
{<br />
    if(last == length - 1) <br />
    {<br />
        cout<<"\tSorry the queue is full, please wait";<br />
        return;<br />
    }<br />
    if(first == -1)<br />
    {<br />
        first=0;<br />
    }<br />
    last=last+1;<br />
    data[last]=out; <br />
    return;<br />
}<br />
<br />
void Queue::show()<br />
{<br />
<br />
}<br />
<br />
//The choice of menu options are executed<br />
void main()<br />
{<br />
<br />
	int StudentID;<br />
    int number;<br />
    int option;<br />
    cout<<"\n\n\tEnter the length of the Queue : ";<br />
    cin>>number;<br />
	while (number>10)<br />
	{<br />
		cout<<"\nMaximum length of queue is set to 10, try again: ";<br />
		cin>>number;<br />
	}<br />
    Queue place(number);<br />
    do<br />
    {<br />
        option = menu();<br />
        switch(option)<br />
        {<br />
            case 1:<br />
<br />
			cout<<"\n\t* * Valid student numbers between 1 and 500 only * *\n";<br />
			cout<<"\nEnter the student number : ";<br />
            cin>>StudentID;<br />
			while (StudentID <1 || StudentID>500)<br />
			{<br />
				cout<<"Invalid entry try again";<br />
				cin>>StudentID;<br />
			}<br />
			place.push(StudentID);<br />
            cout<<"\n\tStudent number "<<StudentID<<" has been inserted into queue.";<br />
			break;<br />
            <br />
			case 2:<br />
            int StudentID;<br />
            StudentID=place.pop();<br />
            if(StudentID==0)<br />
            {<br />
                cout<<"\n\tSorry no students to see the queue is empty";<br />
            }<br />
            else<br />
            {<br />
                cout<<"\n\tStudent "<<StudentID<<" deleted from queue.";<br />
            }<br />
            break;<br />
			case 3:<br />
			break;<br />
            case 4:<br />
            {};<br />
            break;<br />
            default: cout<<"\nIncorrect entry, try again with 1,2,3 or 4.";<br />
        }<br />
    }<br />
    while (option!=4);<br />
}