#include <stdio.h>
#include <unistd.h>
#include <omp.h>

int main() {

    int i, j;
    int n = 5;

    // for             --> imbalance
    // for collapse(2) --> undefined: inner-loop depends on outer-loop (j <= i)
    // task            --> balance

    #pragma omp parallel
    {
        #pragma omp single private(i,j)
        for (i = 0; i < n; i++)
            for (j = 0; j <= i; j++)
            #pragma omp task
            {
                printf("[%d]: (%d, %d)\n", omp_get_thread_num(), i, j);
                sleep(1);
            }
    }

    return 0;
}