react-tree-graph | react library for generating a graphical tree | Frontend Framework library

You could first create a Map that has as keys the name property values, and as corresponding values the (unfinished) result objects. They start off with just the name property.

Then you can iterate the children information in the input, to wire the children into the above mentioned result objects, which can be done efficiently using the name as key in the Map.

Whenever you wire a child object into a parent object, you know that child is not a top-level object in the final result. So starting with all nodes, you would trim that list (a Set) all those nodes that occur in a children array. This will leave you with only the top level nodes, which in its array form represents the desired output.

Implementation: