1517 u Calculate e

#include <iostream>
using namespace std;

// 5  120
// 6  720
// 7  5040
// 8  40320
// 9  362880

int main(){
cout<<"n e"<<endl;
cout<<"- -----------"<<endl;
double ans[10] = {1,2,2.5,6,24,120,720,5040,40320,362880};
for(int i=0;i<3;++i){
cout<<i<<" "<<ans[i]<<endl;
}
cout.precision(10);
for(int i=3;i<10;++i){
ans[i] = ans[i-1] + (double)1.0/ans[i];
cout<<i<<" "<<ans[i]<<endl;
}

return 0;
}