diamond with line in middle

#include<iostream>
using namespace std;
int main(){
    cout<<"Masukkan angka :  ";

    int size;
    cin>>size;

    int z=1;
    for ( int i=0; i<=size-2; i++){
        for (int j=size; j>i; j--){
          cout<<" ";
        }

        cout<<"*";

        if (i>0){
          for ( int k=1; k<=z; k++){
            cout<<" ";
          }
          z+=2;
          cout<<"*";
        }
        cout<<endl;
    }

    for(int a=0; a<size; a++){
        cout << " *";
    }
    cout << endl;

    z-=4;

    for (int i=0; i<=size-2; i++){
        for (int j=0; j<=i+1; j++){
          cout<<" ";
        }

        cout<<"*";

        for (int k=0; k<=z+1; k++){
          cout<<" ";
        }
        z-=2;

        if (i!=size-2){
          cout<<"*";
        }
        cout<<endl;
    }
    return 0;
}