#include <cstdio>
#include <omp.h>
int main(int argc, char *argv[])
{
omp_set_num_threads(4);
#pragma omp parallel
{
int id = omp_get_thread_num();
int nproc = omp_get_num_threads();
cout << "Hello world with id number and processes " << id << nproc << endl;
}
return 0;
}
Variables declared outside of the parallel region are shared by all threads If a variable like id is declared outside of the
#pragma omp parallel,
it would have been shared by various the threads, possibly causing erroneous output