// optimal number of threads

#include "work.h"

#include <thread>
#include <vector>

int main()
{
    const std::size_t T = std::thread::hardware_concurrency();

    std::vector<std::thread> t;

    for (std::size_t i = 0; i < T; ++i)
        t.emplace_back(work, i * N / T, (i + 1) * N / T);

    for (auto &i : t)
        i.join();
}