public AstronomicalChart Build(string input)
{
input = input.Trim();
var commands = Split(input).ToList();
var objects = new Dictionary <string, AstronomicalObject>();
AstronomicalChart result = null;
foreach (var command in commands)
{
AstronomicalObject primary;
if (!objects.TryGetValue(command.Item1, out primary))
{
primary = new AstronomicalObject(command.Item1);
objects.Add(primary.Name, primary);
}
if (result == null && primary.Name == "COM")
{
result = new AstronomicalChart(primary);
}
AstronomicalObject satellite;
if (!objects.TryGetValue(command.Item2, out satellite))
{
satellite = new AstronomicalObject(command.Item2);
objects.Add(satellite.Name, satellite);
}
primary.AddSatellite(satellite);
}
return(result);
}
public void AddSatellite(AstronomicalObject satellite)
{
if (satellite == null)
{
throw new ArgumentNullException(nameof(satellite));
}
satellite.SetPrimary(this);
this.satellites.Add(satellite);
}
private IEnumerable <AstronomicalObject> GetParents(AstronomicalObject start)
{
var current = start;
do
{
yield return(current);
current = current.Primary;
}while (current != null);
}
private AstronomicalObject SearchGraph(AstronomicalObject start, string searchFor)
{
if (start.Name == searchFor)
{
return(start);
}
foreach (var satellite in start.Satellites)
{
var result = SearchGraph(satellite, searchFor);
if (result != null)
{
return(result);
}
}
return(null);
}
private AstronomicalObject FindCommonAncestor(IEnumerable <AstronomicalObject> pathToStart, IEnumerable <AstronomicalObject> pathToDestination)
{
var path1 = pathToStart.ToList();
var path2 = pathToDestination.ToList();
AstronomicalObject lastMatch = null;
for (int i = 0; i < Math.Min(path1.Count, path2.Count); i++)
{
if (path1[i].Name == path2[i].Name)
{
lastMatch = path1[i];
}
else
{
break;
}
}
return(lastMatch);
}
public void SetPrimary(AstronomicalObject primary)
{
Primary = primary ?? throw new ArgumentNullException(nameof(primary));
}