Runtime??

[DrJones]

Shouldn't a for loop which loops 10 time have a greater runtime than a for loop with 5 loops?
If so, how come am I getting the same result in both cases??

int main(int argc, const char * argv[])
{
 chrono::time_point<chrono::system_clock> start,end;
    chrono::duration<float,micro> elapsed_seconds;
    ofstream myfile;
    int n = 0;
    
    cout << "computes f(n), what should n be?" << endl;
    cin >> n;
    myfile.open("stats.txt");
    
    for (int i = 0; i<=n; i++) {
        myfile << i ;
        start = chrono::system_clock::now();
        fibonacci(i); // not recursive method
        end  =  chrono::system_clock::now();
        elapsed_seconds = end-start;
        //cout << "finished computation - normal f("<<i<<") " << "time: "   << elapsed_seconds.count() << "ms" << endl;
        myfile << ";" << elapsed_seconds.count() << endl;
}
return 0
}

[helios]

Maybe fibonacci() ends so quickly that chrono::system_clock::now() doesn't have enough precision. Maybe the compiler noticed that fibonacci() doesn't have any side effects and its return value is discarded, so it decided to simply not call it.

[DrJones]

I've tested it by printing the result, and so no of the values gets discarded.
Precision might swell be the reason, until i tried a ratio of 1,100000000, and it still gave me results 1*10000000 and 0.