C++ chrono

chrono

• <chrono> 라이브러리

  • C++11

  • 실행 시간 측정(Run Time Measurement)에 사용되며, 시간을 비교적 정밀하게 측정할 수 있다.

  #include <iostream>
  #include <vector>
  #include <algorithm>
  #include <random>
  #include <chrono>
  
  using namespace std;
  
  class Timer
  {
    using clock_t = std::chrono::high_resolution_clock;
    using second_t = std::chrono::duration<double, std::ratio<1>>;
  
    std::chrono::time_point<clock_t> start_time = clock_t::now();
  
  public:
    void elapsed()
    {
      std::chrono::time_point<clock_t> end_time = clock_t::now();
  
      std::cout << std::chrono::duration_cast<second_t>(end_time - start_time).count() << std::endl;
    }
  };
  
  int        main()
  {
    random_device    rnd_device;
    mt19937            mersenne_engin{ rnd_device() };
  
    vector<int>        vec(100000);
    for (size_t i = 0; i < vec.size(); ++i)
      vec[i] = i;
  
    std::shuffle(begin(vec), end(vec), mersenne_engin);
  
    /*for (auto& e : vec) cout << e << ' ';
    cout << endl;*/
  
    Timer timer;
  
    std::sort(begin(vec), end(vec));
  
    timer.elapsed();
  
    /*for (auto& e : vec) cout << e << ' ';
    cout << endl;*/
  }