c++ program that display following triangle pattern.

for n=3;

pattern:      

        1
        1 1
        1 1 2



#include <iostream>
using namespace std;

int main()
{
int i,j,k,f1,f2,f3;
//input from user
cout<<"Enter a number ";
cin>>k;



for(i=1;i<=k;i++)
{
f3=f2=1;
f1=0;
for(j=1;j<=i;j++)
{

cout<<f3<<" ";
f3=f1+f2;
f1=f2;
f2=f3;
}
cout<<"\n";
}
return 0;
}