public int Between(IProgrammer programmerFrom, IProgrammer programmerTo)
{
if (programmerFrom.Equals(programmerTo))
{
return(0);
}
var parents = BuildParentPointers(programmerFrom);
return(ShortestPath(programmerFrom, programmerTo, parents));
}
private static int ShortestPath(IProgrammer programmerFrom, IProgrammer programmerTo, Dictionary <IProgrammer, IProgrammer> parents)
{
var degreesOfSeparation = 0;
IProgrammer parentProgrammer = programmerTo;
while (!programmerFrom.Equals(parentProgrammer))
{
parentProgrammer = parents[parentProgrammer];
degreesOfSeparation++;
}
return(degreesOfSeparation);
}