#include <QCoreApplication>
#include <mutex>
#include <thread>
#include <vector>
#include <fstream>
#include <iostream>
#include <atomic>

static std::atomic<unsigned int> nLatestProcessed = {0};
static const unsigned int nMaxToProcess = 200;
static const unsigned int nMaxRoot = 4000000000;
//std::mutex mInt;
std::mutex mOutput;

unsigned int IncreaseLatestNum()
{
  //std::lock_guard<std::mutex> lk(mInt);
  return nLatestProcessed.fetch_add(1, std::memory_order_relaxed);
}

void ProcessNumber()
{
  unsigned int ToProcess;
  unsigned long long x;
  unsigned long long y;
  unsigned long long z;

  do {
    ToProcess = IncreaseLatestNum();
    if (ToProcess >= nMaxToProcess) {
        break;
    }
    z = sqrt(ToProcess);
    if (z*z == ToProcess) {
        continue;
    }
    for (x = 1; x < nMaxRoot; ++x) {
        y = x*x*ToProcess + 1;
        z = sqrt(y);
        if (z*z == y) {
          std::lock_guard<std::mutex> lk(mOutput);
          std::cout << std::this_thread::get_id() << ": " << ToProcess << ": (" << z << ", " << x << ")" << std::endl;
          break;
        }
    }
    if (x == nMaxRoot) {
        std::lock_guard<std::mutex> lk(mOutput);
        std::cout << std::this_thread::get_id() << ": " << ToProcess << ": (none, none)" << std::endl;
        break;
    }
  }
  while (true);
}

int main(int argc, char *argv[])
{
    std::vector<std::thread> v;

    QCoreApplication a(argc, argv);

    for (unsigned int var = 0; var < std::thread::hardware_concurrency(); ++var) {
      v.push_back(std::thread(ProcessNumber));
    }

    std::for_each(v.begin(),v.end(), std::mem_fn(&std::thread::join));

    std::cout << "done" << std::endl;
    return a.exec();
}