tugas deret segitiga bintang

#include
void main()
{
int x, y, a, z;
cout<<"masukan nilai segitiga: ";
cin>>x;
y=1;
z=a;
for (y=1;y<=x;y++)
{
for (a=1;a<=y;a++)
{
cout<<" ";
}
for(z=x;z>=y;z--)
{
cout<<"* ";
}
cout< }
}