static Graph LoadBags(string input)
{
var graph = new Graph();
foreach (var line in FileIterator.Lines(input))
{
var groups = line.Groups("^(.+) bags contain (.+)\\.$");
var bagType = groups[0];
var bagNode = graph.GetOrCreate(bagType, () => (new(), new()));
if (groups[1] != "no other bags")
{
var children = groups[1].Split(',');
foreach (var child in children)
{
groups = child.Groups("(\\d+) (.+) bag");
bagNode.Item2.Add((int.Parse(groups[0]), groups[1]));
var childNode = graph.GetOrCreate(groups[1], () => (new(), new()));
childNode.Item1.Add(bagType);
}
}
}
return(graph);
}