time&chronos

#include <iostream>
#include <chrono>
#include <ctime>
 
using namespace std;
 
long fibonacci(int n) {
    if (n < 3) return 1;
    return fibonacci(n - 1) + fibonacci(n - 2);
}
 
int main() {
        chrono::time_point<chrono::high_resolution_clock> start, end;
        start = chrono::high_resolution_clock::now();
        // function to test comes here
		fibonacci(i);
        end = chrono::high_resolution_clock::now();
        chrono::duration<double> elapsed_seconds = end - start;
        cout << elapsed_seconds.count() << "s" << endl;
    while (1) {}
    return 0;
}