void load_demo_9pts_map(MAP &pts)
{
pts.clear();
for (size_t i=0;i<demo9_N;i++)
pts.insertPoint(demo9_xs[i],demo9_ys[i],demo9_zs[i]);
}
///making hashtable null to be used for next iteration
void make_root_null() {
for ( int i = 0; i < s; i++ ) {
hashmap.clear();
}
}