Распараллеливание

#include <iostream>
#include <vector>
#include <cmath>
#include <functional>
#include <random>
#include <algorithm>
#include <ctime>
 
#include "thread.h"
#include "criticalsection.h"
 
struct args
{
  int *arr,
       begin,
       end,
       min;
};
 
DWORD WINAPI min_elem(LPVOID param)
{
  args *_arg = static_cast<args*>(param);
  int min = _arg->arr[_arg->begin];
  for(int i = _arg->begin + 1; i <= _arg->end; ++i)
    if(min > _arg->arr[i])
      min = _arg->arr[i];
  _arg->min = min;
}
 
int main()
{
  SetConsoleCP(1251);
  SetConsoleOutputCP(1251);
 
  const int n = 1000000, nn = 2;
  int *a = new int[n];
  my::thread thr[nn];
  args arg[nn];
 
  auto rnd = std::bind(std::uniform_int_distribution<int>(-10000, 10000),
                       std::mt19937(time(nullptr)));
  std::generate(a, a + n, rnd);
 
  arg[0].arr = arg[1].arr = a;
  arg[0].begin = 0;
  arg[0].end = n / 2;
  arg[1].begin = n / 2 + 1;
  arg[1].end = n - 1;
 
  thr[0].create(min_elem, LPVOID(&arg[0]));
  thr[1].create(min_elem, LPVOID(&arg[1]));
 
  std::cout << std::min({arg[0].min, arg[1].min});
 
  delete[] a;
 
  return 0;
}

void my::thread::create(LPTHREAD_START_ROUTINE lpStartAddress, LPVOID lpParameter)
{
  hThread = CreateThread(NULL, 0, lpStartAddress, lpParameter, 0, &ThreadId);
  //WaitForSingleObject(hThread, INFINITE); тут не знаю как надо
}