Simple algorithm to eliminate circular references

We are starting with Neuron XYZ

Begin with array of all neurons
Create a dictionary
Fill dictionary with the GUID of every neuron as the key (value doesn’t really matter)
Now remove neuron XYZ from the dictionary (ie. itself)
Now iterate through every neuron that XYZ is currently connected to and remove those from the map
If we find those in map then repeat removing connected neurons of that neuron - but if the neuron is already present in the map then we are done for that particular neuron.

Example code in Lua:

function CreateNeuronMap(N)
   local Map = {}
   for i=1, #N do
      Map[i] = true
   end
   return Map
end

function FindSuitors(Neurons, Map, ID)
   if Map[ID] then
      Map[ID]= nil
      for i=1, #Neurons[ID] do
         FindSuitors(Neurons, Map, Neurons[ID][i])
      end
   end
end

function main()
   local Neurons = {}
   Neurons[1] = {2,3}
   Neurons[2] = {2}
   Neurons[3] = {}
   local Map = CreateNeuronMap(Neurons)
   FindSuitors(Neurons, Map,  3)
   trace(Map)
end