Measuring Time on Codeforces

#include <stdint.h>
#include <stdio.h>
#include <windows.h>

using namespace std;

// the function f() does some time-consuming work
void f ()
{
  volatile double d = 0;
  for (int n = 0; n < 25000; ++n)
    for (int m = 0; m < 100000; ++m)
      d += d * n * m;
}

int main ()
{
  HANDLE hProcess;
  hProcess = GetCurrentProcess ();
  FILETIME CreationTime;
  FILETIME ExitTime;
  FILETIME KernelTime;
  FILETIME UserTime;
  f ();
  GetProcessTimes (hProcess, &CreationTime, &ExitTime, &KernelTime, &UserTime);
  uint64_t kernel = ((uint64_t) KernelTime.dwHighDateTime << 32) |
    KernelTime.dwLowDateTime;
  uint64_t user = ((uint64_t) UserTime.dwHighDateTime << 32) |
    UserTime.dwLowDateTime;
  printf ("%.0lf ms + %.0lf ms ~ %.0lf ms\n",
    kernel / 10000.0, user / 10000.0, (kernel + user) / 10000.0);
  return 0;
}