This is an implementation of static queue ADT

StaticQueue.cpp

#include<iostream>
#include<conio.h>
#define size 2
using namespace std;
class Queue{
	int a[size],front,rear;
	public: Queue(){
		front = rear = -1;
	}
	bool isEmpty(){
		if(front == -1 && rear == -1)
		return true;
		else
		return false;
	}
	bool isFull(){
	if((rear+1)%size == front)
	return true;
	else
	return false;
	}
	void enqueue(int x){
		if(isEmpty() == true){
			front = rear = 0;
			a[rear] = x;
			display();
			return;
		}
		if(isFull() == true){
			cout<<"Can't add more elements"<<endl;
			display();
			return;
		}
		rear = (rear + 1) % size;
		a[rear] = x;
		display();
	}
	void dequeue(){
		if(front != -1 && front == rear){
			cout<<"Deleted Element is: "<<a[front]<<endl;
			front = rear = -1;
			display();
			return;
		}
		if(isEmpty() == true){
			cout<<"No elements to delete"<<endl;
			display();
			return;
		}
		cout<<"Deleted element is: "<<a[front]<<endl;;
		front = (front + 1) % size;
		display();
	}
	void display(){
		int l = (rear+size-front)%size + 1;
		cout<<"Queue is: ";
		if(isEmpty() == true){
			cout<<"Empty"<<endl;
			return;
		}
		for(int i=0; i<l; i++){
			cout<<a[(front+i)%size]<<" ";
		}
		cout<<endl;
	}
};
int main(){
	Queue q;
	q.dequeue();
	q.enqueue(3);
	q.enqueue(5);
	q.dequeue();
	q.dequeue();
	q.dequeue();
	q.enqueue(5);
	q.enqueue(4);
	q.enqueue(6);
}