hread::hardware_concurrency().
          If the number is 1 or 0, the algorithm runs with only 1 thread.
        </p>
<p>
          The number of threads is not a fixed number, but is calculated in each
          execution. The number of threads passed can be greater than the number
          of hardware threads on the machine. We can pass 100 threads in a machine
          with 4 HW threads, and in the same mode we can pass a function as (std::thread::hardware_concurrency()
          / 4 ). If this value i