Simulation check in at an airport counter with 2 queues and 2 first class counters for the first class queue and 3 coach class counters for the coach queue.

Airport Check-in simulation

//Hyo Chang Kim
//Kim-CS610-2017-programming assignment 1
//Professor Ali Mili
/*
Input:
1.  Duration of Simulation
2.  Average Coach Class Passenger Arrival Time
3.  Average Coach Class Service Time
4.  Average First Class Passenger Arrival Time
5.  Average First Class Service Time

Processing:
1.  Create Queue
2.  Use conditional statements to:
    1.  Enqueue Passengers
    2.  Dequeue Passengers based on service time and arrival time
4.  Calculate Output

Output:
1.  Total Simulation time
2.  Maximum length of Queue
3.  Maximum wait time
4.  Maximum average time
5.  Rate of Occupancy per station
*/


#include <iostream>
#include <string>
#include <iomanip>

using namespace std;

class Cnode
{
    int value;                              //integer value representing passenger
    Cnode *next;                            //hold pointer address to next node in the list
    friend class Clist;                     //provide access to this class by Clist
    friend class Queue;                     //provide access to this class by Queue
};

class Clist
{
public:
    Clist();                                //constructor
    ~Clist();                               //destructor
    bool empty() const;                     //check empty
    const int& front() const;               //returns node referenced by the cursor
    const int& back() const;                //returns cursor
    void advance();                         //advances cursor to next node on the list
    void add(const int& e);                 //inserts new node at "e" and makes it the cursor
    void remove();                          //removes the front node (immediately after the cursor).
private:
    Cnode *cursor;                          //hold pointer address to cursor node
    friend class Queue;                     //provide access to this class by Queue
};

class Queue
{
public:
    Queue();                                //constructor - no destructor (use destructor from CList class)
    bool empty() const;                     //check empty
    const int& front() const;               //returns node referenced by the cursor
    void enqueue(const int& e);             //inserts at end; becomes new cursor
    void dequeue();                         //removes from front
    void display();                         //show progression of enq/deq;show content
    void showFront();                       //show first top
    int count();                            //show number of elements in queue
private:
    Clist C;
    int n;
    
};

Clist::Clist()                              //constructor
{
    cursor = NULL;
}

Clist::~Clist()                             //destructor
{ while(!empty()) remove(); }

Queue::Queue()                              //constructor
: C(), n(0) {}

bool Clist::empty() const                   //check empty
{
    if(cursor == NULL)
        return true;
    else
        return false;
}

bool Queue::empty() const                   //check empty
{ return n == 0; }

const int& Queue::front() const             //returns front node or empty
{
    if (empty())
        cout << "Queue is empty\n";
    return C.front();
}

const int& Clist::front() const             //returns front node or empty
{
    if(empty())
        cout << "Queue is empty\n";
    return cursor-> next-> value;
}

const int& Clist::back() const              //returns cursor or empty
{
    if(empty())
        cout << "Queue is empty\n";
    return cursor-> value;
}

void Clist::advance()                       //advances cursor to next node on list
{
    if(empty())
        cout << "Queue is empty\n";
    cursor = cursor-> next;
}

int main()
{
    Queue FC;                               //create First Class queue
    Queue CC;                               //create Coach Class queue
    
    double durationOfCheckIn;               //initialize input variables
    double CCAverageArrivalTime;
    double CCAverageServiceTime;
    double FCAverageArrivalTime;
    double FCAverageServiceTime;
    
    cout << "Please enter following parameters to begin simulation " << endl;  //get input variables
    cout << endl;
    cout << "Duration of check-in (in whole minutes): " << endl;
    cin >> durationOfCheckIn;
    cout << "Average arrival time interval for coach class passengers (in whole minutes): " << endl;
    cin >> CCAverageArrivalTime;
    cout << "Average time each passenger spends at coach class service station (in whole minutes): " << endl;
    cin >> CCAverageServiceTime;
    cout << "Average arrival time interval for first class passengers (in whole minutes): " << endl;
    cin >> FCAverageArrivalTime;
    cout << "Average time each passenger spends at first class service station (in whole minutes): " << endl;
    cin >> FCAverageServiceTime;
    
    double FCSS1 = 0;                       //initialize counter/output variables
    double FCSS2 = 0;
    double FCC1 = 0;
    double FCC2 = 0;
    int t = 0;
    int i = 0;
    while(t < durationOfCheckIn)
    {
        if(i == FCAverageArrivalTime)       //loop enqueues passengers to queue
        {
            FC.enqueue(1);
            i = 0;
        }
        if(FCSS1 == 0)                      //checks if counter is open
        {
            FC.dequeue();
            FCSS1 = FCAverageServiceTime;
            FCC1++;                         //increments and keeps track of customers served
        }
        else if(FCSS2 == 0)
        {
            FC.dequeue();
            FCSS2 = FCAverageServiceTime;
            FCC2++;
        }
        else
        {
            FCSS1--;                        //decrements service time for customer at counter
            FCSS2--;
        }
        t++;                                //increments time from opening of check-in counter
        i++;                                //increments time between passenger arrival
    }
    
    double CCSS1 = 0;                       //initialize variables
    double CCSS2 = 0;
    double CCSS3 = 0;
    double CCC1 = 0;
    double CCC2 = 0;
    double CCC3 = 0;
    int u = 0;
    int v = 0;
    while(u < durationOfCheckIn)
    {
        if(v == CCAverageArrivalTime)       //loop enqueues passengers to queue
        {
            CC.enqueue(2);
            v = 0;
        }
        if(CCSS1 == 0)                      //checks if counter is open
        {
            CC.dequeue();
            CCSS1 = CCAverageServiceTime;
            CCC1++;                         //increments and keeps track of customers served
        }
        else if(CCSS2 == 0)
        {
            CC.dequeue();
            CCSS2 = CCAverageServiceTime;
            CCC2++;
        }
        else if(CCSS3 == 0)
        {
            CC.dequeue();
            CCSS3 = CCAverageServiceTime;
            CCC3++;
        }
        else
        {
            CCSS3 --;                       //decrements service time for customer at counter
            CCSS2 --;
            CCSS1 --;
        }
        u++;                                //increments time from opening of check-in counter
        v++;                                //increments time between passenger arrival
    }
    
    double FCsimTotal;                      //begin output variables
    FCsimTotal = (FCC1 + FCC2 + FC.count())*FCAverageServiceTime;
    cout << "Total Simulation Time for First Class is: " << FCsimTotal << " minutes" << endl;
    double CCsimTotal;
    CCsimTotal = (CCC1 + CCC2 + CCC3 + CC.count())*CCAverageServiceTime;
    cout << "Total Simulation Time for Coach Class is: " << CCsimTotal << " minutes" << endl;
    cout << endl;
    
    cout << "Passengers serviced at First Class Service Station #1: " << FCC1 << endl;
    cout << "Passengers serviced at First Class Service Station #2: " << FCC2 << endl;
    cout << "Passengers serviced at Coach Class Service Station #1: " << CCC1 << endl;
    cout << "Passengers serviced at Coach Class Service Station #2: " << CCC2 << endl;
    cout << "Passengers serviced at Coach Class Service Station #3: " << CCC3 << endl;
    cout << endl;
    cout << "Maximum length of queue for First Class: " << FC.count() << endl;
    cout << "Maximum length of queue for Coach Class: " << CC.count() << endl;
    cout << endl;
    cout << setprecision(2) << fixed << showpoint;
    cout << "Average waiting time for First Class is " << (FC.count()/FCAverageServiceTime) << " minutes" <<endl;
    cout << "Average waiting time for Coach Class is " << (CC.count()/CCAverageServiceTime) << " minutes" <<endl;
    cout << endl;
    cout << "Maximum waiting time for First Class is " << (FC.count()*FCAverageServiceTime/2) << " minutes" << endl;
    cout << "Maximum waiting time for Coach Class is " << (CC.count()*CCAverageServiceTime/3) << " minutes" <<endl;
    cout << endl;
    double rateFCSS1 = ((FCC1*FCAverageServiceTime)/durationOfCheckIn)*100;
    cout << "Rate of occupancy for FC station 1 is " << rateFCSS1 << "%" << endl;
    double rateFCSS2 = ((FCC2*FCAverageServiceTime)/durationOfCheckIn)*100;
    cout << "Rate of occupancy for FC station 2 is " << rateFCSS2 << "%" << endl;
    cout << endl;
    double rateCCSS1 = ((CCC1*CCAverageServiceTime)/durationOfCheckIn)*100;
    cout << "Rate of occupancy for CC station 1 is " << rateCCSS1 << "%" << endl;
    double rateCCSS2 = ((CCC2*CCAverageServiceTime)/durationOfCheckIn)*100;
    cout << "Rate of occupancy for CC station 2 is " << rateCCSS2 << "%" << endl;
    double rateCCSS3 = ((CCC3*CCAverageServiceTime)/durationOfCheckIn)*100;
    cout << "Rate of occupancy for CC station 3 is " << rateCCSS3 << "%" << endl;
    cout << endl;
    
    return 0;
}

void Clist::add(const int& e)               //insert node
{
    Cnode *v = new Cnode;
    v-> value = e;
    v-> next = NULL;
    if(cursor == NULL)
    {
        v-> next = v;
        cursor = v;
    }
    else
    {
        v-> next = cursor-> next;
        cursor-> next = v;
    }
}

void Queue::enqueue(const int& e)           //insert node at back
{
    C.add(e);
    C.advance();
    n++;
}

void Clist::remove()                        //remove node
{
    Cnode *old = cursor-> next;
    if(old == cursor)
    {
        cursor = NULL;
    }
    else
    {
        cursor-> next = old-> next;
    }
    delete old;
}

void Queue::dequeue()                       //remove node from front.
{
    if(empty())
    {
        //cout << "Queue is empty\n";
        return;
    }
    C.remove();
    n--;
}

void Queue::display()                       //display content of queue
{
    if(empty())
    {
        cout << "Queue is empty\n";
    }
    else
    {
        int j = 0;
        Cnode* temp = C.cursor-> next;
        for(int i = 1; i <= this-> count(); i++)
        {
            //cout << temp-> value << " " << endl;
            j++;
            temp = temp-> next;
        }
        cout << "number in queue: " << j << endl;
    }
}

int Queue::count()                          //display size of queue
{
    Cnode *v;
    v = C.cursor;
    int c = 0;
    if(C.cursor == NULL)
        return 0;
    else
        c++;
    while(v-> next != C.cursor)
    {
        c++;
        v = v-> next;
    }
    return c;
}

void Queue::showFront()                     //show top
{
    if(empty())
        cout << "Queue is empty\n";
    else
        cout << "Number at front is: " << C.cursor-> next-> value;
}