text: #include <io_utils.h>
  #include <time_utils.h>
  #include <time.h>
  
  #define PI 3.1415926
  
  void DoHardWork() {
    double sum = 0;
    for (int i = 0; i < 10000000; ++i) {
      sum += i * i / PI;
    }
    PRINT_DOUBLE(sum);
  }
  
  int main() {
    time_t start_time = time(NULL);
    DoHardWork();
    time_t end_time = time(NULL);
    double diff = difftime(start_time, end_time);
    PRINT_DOUBLE(diff);
  
    long_time_t start_time_ms = TimeInMillisecond();
    DoHardWork();
    long_time_t end_time_ms = TimeInMillisecond();
    PRINT_LLONG(end_time_ms - start_time_ms);
  
    clock_t start_time_c = clock();
    DoHardWork();
    clock_t end_time_c = clock();
    PRINT_DOUBLE((end_time_c - start_time_c) * 1.0 / CLOCKS_PER_SEC);
    return 0;
  }
  