Question

Implement a generic queue.  Use the code below for main().

main()

{

int i, x;

float y;

char z;

Queue<int> A;

Queue<float> B;

Queue<char> C;

ifstream in;

in.open("int.txt");

for (i = 0; i < 100; i++){

        in >> x;

        A.enqueue(x);

    }

cout << A.dequeue() << endl;;

for (i = 0; i < 12; i++)

        A.enqueue(i);

cout << A.dequeue() << endl;

cout << A.dequeue() << endl;

cout << "Dequeueing: "<< A.dequeue()<< endl;

while (!A.isEmpty())

     cout  << A.dequeue() << "  ";

if (A.isEmpty())

      cout << "Integer Queue Is Empty "  << endl;

in.close();

cout << endl << "Now for the floating point numbers...." << endl;

in.open("float.txt");

for (i = 0; i < 100; i++){

        in >> y;

        B.enqueue(y);

    }

cout << "Here are the first ten:" << endl;

for (i = 0; i < 10; i++){

    cout << B.dequeue() << endl;

    }

in.close();

in.open("char.txt");

for (i = 0; i < 100; i++){

        in >> z;

        C.enqueue(z);

    }

cout << "Here are the characters" << endl;

while (!C.isEmpty()){

    cout << C.dequeue();

    }

in.close();

}

Answer 1

GENERIC QUEUE

Below is the implementation of a Generic Queue using Linked List :

#include<iostream>

#include <fstream>
using namespace std;

template <typename T>
class Node {
public :
T data;
Node<T> *next;
  
Node(T data) {
this -> data = data;
next = NULL;
}
};

template<typename T>
class Queue {

Node <T>*head;
Node <T>*tail;
int size;
  
public :
  
  
Queue() {
size=0;
head=NULL;
tail=NULL;
}
  
void enqueue(T data) {
if(head==NULL)
{
Node<T> *n=new Node<T>(data);
head=n;
tail=n;
size++;

}
else
{
Node<T> *n=new Node<T>(data);
tail->next=n;
tail=n;
size++;
}
}
  
int getSize() {
return size;
  
}
  
bool isEmpty() {
  
return size==0;   
}
  
T dequeue() {
// Return 0 if queue is empty
if(size==0)
return 0;
else
{
Node <T> *n=new Node <T> (head->data);
head=head->next;
size--;
return n->data;
  
}
}
  
T front() {
// Return 0 if queue is empty
if(size==0)
return 0;
else
return head->data;
}
};