PROGRAM PIRAMIDA BINTANG C++

#include <iostream.h>
#include <conio.h>
int main(void){

 int x,z,bil;
 cout<<"--PROGRAM PIRAMID--"<<endl;
 cout<<"Masukkan Tinggi Piramid :";
 cin>>bil;

 for(x=1; x<=bil; x++){
  for(z=bil; z>=x; z--)
  cout<<" ";

  for(z=x;z<2*x;z++)
  {
   cout<<"*";
  }
  for(z=2*(x-1);z>=x; z--)
  {
   cout<<"*";
  }
  cout<<"\n";
 }
 getch();
 return 0;
}