#include <stdlib.h>

void etics_external_init(const int n_total, const double length_scale);
void etics_external_grav(const double* const A, const int n_act, double x_act[][3], double pot_act[], double a_act[][3]);

int main()
{
    const int n_total = 1024;
    etics_external_init(n_total, 1.);

    srand(19640916);

    double x_act[n_total][3], pot_act[n_total], a_act[n_total][3];
    for (int i = 0; i < n_total; i++) {
        x_act[i][0] = rand()/(double)RAND_MAX;
        x_act[i][1] = rand()/(double)RAND_MAX;
        x_act[i][2] = rand()/(double)RAND_MAX;
    }

    double A[2048];
    for (int i = 0; i < 2048; i++) {
        A[i] = rand()/(double)RAND_MAX;
    }

    etics_external_grav(A, n_total, x_act, pot_act, a_act);
}