chrono

system_clock::time_point start = system_clock::now();
system_clock::time_point end = system_clock::now();
nanoseconds nano = end - start;
cout << "경과시간(나노초 ns) : " << nano.count() << endl;

chrono::system_clock::time_point EndTime = chrono::system_clock::now();
chrono::duration<double> DefaultSec = EndTime - StartTime;
chrono::nanoseconds nano = EndTime - StartTime;
chrono::microseconds micro = chrono::duration_cast<chrono::microseconds>(EndTime - StartTime);
chrono::milliseconds mill = chrono::duration_cast<chrono::milliseconds>(EndTime - StartTime);
chrono::seconds sec = chrono::duration_cast<chrono::seconds>(EndTime - StartTime);
chrono::minutes min = chrono::duration_cast<chrono::minutes>(EndTime - StartTime);
chrono::hours hour = chrono::duration_cast<chrono::hours>(EndTime - StartTime);

cout << "for문 실행 시간(default) : " << DefaultSec.count() << endl;
cout << "for문 실행 시간(nanoseconds) : " << nano.count() << endl;
cout << "for문 실행 시간(microseconds) : " << micro.count() << endl;
cout << "for문 실행 시간(milliseconds) : " << mill.count() << endl;
cout << "for문 실행 시간(seconds) : " << sec.count() << endl;
cout << "for문 실행 시간(minutes) : " << min.count() << endl;
cout << "for문 실행 시간(hour) : " << hour.count() << endl;