c++ program that display following triangle pattern.

for n=3;

pattern:      

        1
        1 2
        3 5 8


 
#include <iostream>
using namespace std;

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


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

for(x=0;x<k-i;x++)
{
cout<<" ";
}
for(j=1;j<=i;j++)
{
cout<<f3<<" ";
f3=f1+f2;
f1=f2;
f2=f3;
}
cout<<"\n";
}
return 0;
}