Double Ended Queue using array in CPP

DEq.cpp

#include <iostream>
using namespace std;

struct queue{
  int size;
  int front;
  int rear;
  int *Q;
};

struct queue p;

void create_queue(int size){
  p.size = size;
  p.rear = p.front = -1;
  p.Q = new int[p.size];
}

void enq_rear(int ele){
  if(p.rear == (p.size-1)){
    cout << "queue is full!" << endl;
  }
  else{
    p.rear++;
    p.Q[p.rear] = ele;
  }
}

void deq_rear(){
  if(p.rear==-1){
    cout << "Queue is empty!" << endl;
  }else{
    p.rear--;
  }
}

void deq_front(){
  if(p.front==p.rear){
    cout << "Queue is empty!" << endl;
  }else{
    p.front++;
  }
}

void enq_front(int ele){
  if(p.front==-1){
    cout << "Cannot Enqueue, Delete using deq_front first!" << endl;
  }else{
    p.Q[p.front] = ele;
    p.front--;
  }
}

void display(){
  if(p.front == p.rear){
    cout << "Queue is Empty!" << endl;
    return;
  }
  for(int i=(p.front+1);i<=p.rear;i++){
    cout << p.Q[i] << " ";
  }
}

void get_front_rear(){
  cout << endl << "Front : " << p.front << " | " << "Rear : " << p.rear << endl;
}

int main(){
  create_queue(20);
  for(int i=1;i<=10;i++){
    enq_rear(i);
  }
  display();
  get_front_rear();
}