Where to start to do a solver in HDK

[ja0335]

Hi,

Im here because I need some lights. Currently I created a simple Vex code to simulate gravity on a set of points using a solver node.

https://youtu.be/1w-swIRCvjA

It was very fun and easy to do it in VEX, but  what I want to do is learn HDK so I don´t have idea how to do it in C++. I've researched a lot and founded writing DOPs could be an option, unfortunately the documentation about writing a simple DOP is not so clear. BW I googled to see if there is a simple example but it looks all the available codes are very old. 

I don´t know if some one may point me in the correct direction to do a simple solver and if writing a custom DOP is the correct way of do it. 

Thank you.