Queue implementation

#include <iostream>

using namespace std;

class Queue{
    int size,f,r,cnt;
    int*a;
    public:
        Queue(int n){
            size=n;
            f=-1;
            r=-1;
            cnt=0;
            a=new int[n];
        }
        void push_front(int x){
            if(cnt==size)cout<<"FULL\n";
            else{
                if(f==-1){
                    f=r=0;
                    a[f]=x;
                }
                else{
                    if(f==0)f=size-1;
                    else f--;
                    a[f]=x;
                }
                cnt++;
                cout<<"push: "<<x<<endl;
            }
        }
        void push_back(int x){
            if(cnt==size)cout<<"FULL\n";
            else{
                if(f==-1){
                    f=r=0;
                    a[f]=x;
                }
                else{
                    if(r==size-1)r=0;
                    else r++;
                    a[r]=x;
                }
                cnt++;
                cout<<"push: "<<x<<endl;
            }
        }
        int pop_front(){
            if(cnt==0)cout<<"Empty\n";
            else{
                int x=a[f];
                if(f==r)f=r=-1;
                else f=(f+1)%size;
                cnt--;
                return x;
            }
        }
        int pop_back(){
            if(cnt==0)cout<<"Empty\n";
            else{
                int x=a[r];
                if(f==r)f=r=-1;
                else if(r==0)r=size-1;
                else r--;
                cnt--;
                return x;
            }
        }
        int front(){
            if(cnt==0)return -1;
            else return a[f];
        }
        int rear(){
            if(cnt==0)return -1;
            else return a[r];
        }
        void show(){
            if(f==-1)cout<<"empty";
            else if(f<=r)for(int i=f;i<=r;i++){
                cout<<a[i]<<" ";
            }
            else{
                for(int i=f;i<size;i++)cout<<a[i]<<" ";
                for(int i=0;i<=r;i++)cout<<a[i]<<" ";
            }
            cout<<endl;
        }
};
int main()
{
   Queue q(6);
   q.show();
   q.push_back(1);
   q.show();
   q.push_back(2);
   q.show();
   q.push_front(5);
   q.show();
   q.push_front(6);
   q.show();
   q.push_back(3);
   q.show();
   q.push_back(4);
   q.show();
   q.push_front(7);
   q.show();
   q.push_front(8);
   q.show();
   q.pop_back();
   q.show();
   q.pop_front();
   q.show();
   return 0;
}