Perulangan While Pada C++ 6

#include <iostream.h>
#include <conio.h>
main()
{
clrscr;
int n,o,p;
o=1;
cout<< "input n: ";
cin>> n;
while (o<=n)
{
p=1;
while (p<=o)
{
cout<<p;
p++;
}
cout<<endl;
o++;
}
getch();
return 0;
}