butterfly shape

#include<iomanip>
using namespace std;
int main() {
    int num;
    cout<<"enter a number"<<endl;
    cin>>num;
    int i=0;
    for(int r=1;r<=num+1;r++){
          for(int c=1;c<=r;c++){
              cout<<'*';}
             
           int b = 2*num-2*r+2;
            for(int s=1;s<=b;s++){
                  
                  cout<<' ';
                  i=i+1;         }
                     for(int c=1;c<=r;c++){
                         cout<<'*'; }
                         cout<<endl;
                     }
                
   for(int r=1;r<=num;r++){
          for(int c=1;c<=num+1-r;c++){
            cout<<'*';}
            
            for(int s=0;s<=2*r-1;s++){
            cout<<' ';
                        }
               for(int c=1;c<=num+1-r;c++){
                cout<<'*';
                           }
                         cout<<endl;         
                
                }
                
                
                     
               
    return 0;
}