entrances = allocate_array<int>(nb_time_steps, nb_locations);
exits = allocate_array<int>(nb_time_steps, nb_locations);
for(int l = 0; l < nb_locations; l++) {
for(int m = 0; m < nb_locations; m++) {
entrances = allocate_array<int>(nb_time_steps, nb_locations);
exits = allocate_array<int>(nb_time_steps, nb_locations);
for(int l = 0; l < nb_locations; l++) {
for(int m = 0; m < nb_locations; m++) {