question practical

q1.cpp

/*                                  AISSCE 2017
 *                                     Set 2
 *
 * This Program stores data of players using a class based queue
 * The Player can be inserted at the rear
 * and the deletion occurs at the front
 *
 * It uses a first come first serve method
 */

#include <iostream.h>
#include <conio.h>
#include <stdio.h>

struct PLAYER {
	// this is a self referenced structure to store data for players
	int Pno;
	char Pname[80];
	char game[80];

	PLAYER *next; // The link to the next player
};

class q{
	// This class maintains the queue using pointers front and rear
	PLAYER *front;
	PLAYER *rear;

  public:
	q() {
		front = rear = NULL; // Initial values of front and rear
	}
	void Qinsert(); //function for insertion at the rear

	void Qdelete(); //function for detelion at the front

	void traverse(); // funtion for displaying the Queue
};

void q::Qinsert() {
	// Definition of Qinsert
	PLAYER *nn = new PLAYER;
	cout << endl << "Enter Player Number : ";
	cin >> nn->Pno;
	cout << "Enter Player Name : ";
	gets(nn->Pname);
	cout << "Enter Player Game : ";
	gets(nn->game);
	nn->next = NULL;

	if (rear == NULL) {
		front = rear = nn;
	} else {
		rear->next = nn;
		rear = nn;
	}

}

void q::Qdelete() {
	// definition of Qdelete
	if (front == NULL) {
		cout << "ERROR: Empty Queue";
	} else if (front == rear) {
		front = rear = NULL;
	} else {
		PLAYER *t = front;
		front = front->next;
		t = NULL;
		delete t;
		cout << endl << "Deleted!!"<<endl;
	}
}

void q::traverse() {
	// definition of Qtraverse
	if(front == NULL) {
		cout << "Empty!!";
	} else {
		cout << endl << "The Queue is : " << endl;
		PLAYER *temp = front;
		while (temp != NULL) {
			cout << "\t" << temp->Pno << "\t" << temp->Pname << "\t" << temp->game << endl;

			temp = temp->next;
		}
	}
}


void main() {
	clrscr();

	q plrs;

	// Insertion of three elements
	plrs.Qinsert();
	plrs.traverse();
	plrs.Qinsert();
	plrs.traverse();
	plrs.Qinsert();
	plrs.traverse();

	// Deletion
	plrs.Qdelete();
	plrs.traverse();

	// Insertion of an element
	plrs.Qinsert();
	plrs.traverse();
	getch();
}