// From http://en.cppreference.com/w/cpp/chrono
#include
#include
#include
unsigned long fibonacci(unsigned n)
{
if (n < 2) return n;
return fibonacci(n-1) + fibonacci(n-2);
}
int main()
{
auto start = std::chrono::system_clock::now();
std::cout << "f(42) = " << fibonacci(80) << '\n';
auto end = std::chrono::system_clock::now();
std::chrono::duration
std::time_t end_time = std::chrono::system_clock::to_time_t(end);
std::cout << "finished computation at " << std::ctime(&end_time) << "elapsed time: " << elapsed_seconds.count() << "s\n"; }