I - u Calculate e

#include<iostream>  
#include<iomanip>  
using namespace std;
double f(int n)
{
    long double a=1;
    for(int i=1;i<=n;i++)a*=i;
    return a;
}
int main()  
{  
    cout << "n e"<<endl<<"- -----------"<<endl;  
    double e=1; 
    cout<<0<<" "<<e<<endl;
    for(int i=1;i<=9;++i)  
    {  
        e+=1/f(i);  
        cout<<i<<" ";  
        if(i!=8)  cout<<setprecision(10)<<e<<endl;  
        else cout<<setprecision(10)<<e<<0<<endl;     
    }    
    //system("pause");
    return 0;
}