How is the algorithm of the dual-track system of Bennliangpin implemented?

How to implement the algorithm of Benranliangpin dual-track system.
It’s a bit similar to a binary tree. There can only be two child nodes under a parent node.

Reply content:

How to implement the algorithm of Benranliangpin dual-track system.
It’s a bit similar to a binary tree. There can only be two child nodes under a parent node.