public List <LuggageRule> ParseRules(List <string> rules)
{
var luggageRules = new List <LuggageRule>();
foreach (var line in rules)
{
var parts = line.Split("bags contain");
var color = parts[0].Trim();
var luggageRule = new LuggageRule(color);
var requiredContent = parts[1].Split(",");
foreach (var requiredBag in requiredContent)
{
if (requiredBag.Contains("no other bags"))
{
continue;
}
var bagParts = requiredBag.Trim(' ').Split(" ");
var requiredBagQuantity = Int32.Parse(bagParts[0]);
var bagColor = bagParts[1] + " " + bagParts[2];
var bagContent = new BagContent(bagColor, requiredBagQuantity);
luggageRule.RequiredContent.Add(bagContent);
}
luggageRules.Add(luggageRule);
}
return(luggageRules);
}
async static Task Main(string[] args)
{
var containsRegex =
new Regex(
"(?'tag'[a-z\\s]+)\\sbags\\scontain(?:\\s(?'bagcount'[0-9]+)\\s(?'bagtype'[a-z\\s]+)\\sbag[s]?,)*\\s(?'bagcount'[0-9])\\s(?'bagtype'[a-z\\s]+)\\sbag[s]?\\.",
RegexOptions.Compiled);
var noBagsRegex = new Regex("(?'tag'[a-z\\s]+)\\sbags\\scontain\\sno\\sother\\sbags\\.",
RegexOptions.Compiled);
using var file = new FileStream("input.txt", FileMode.Open);
using var reader = new StreamReader(file);
var bagDescriptors = new List <BagDescriptor>();
while (true)
{
var line = await reader.ReadLineAsync();
if (line == null)
{
break;
}
var contents = default(BagContent[]);
var name = default(string?);
var match = containsRegex.Match(line);
if (match.Success)
{
name = match.Groups["tag"].Value;
var countCaptures = match.Groups["bagcount"].Captures;
var typeCaptures = match.Groups["bagtype"].Captures;
if (countCaptures.Count != typeCaptures.Count)
{
throw new Exception("Bagcontent mismatch");
}
contents = countCaptures
.Zip(typeCaptures, (a, b) => (count: int.Parse(a.Value), type: b.Value))
.Select(c => new BagContent(c.count, c.type))
.ToArray();
}
else
{
match = noBagsRegex.Match(line);
if (match.Success)
{
name = match.Groups["tag"].Value;
contents = new BagContent[0];
}
else
{
throw new Exception("Unknown line");
}
}
bagDescriptors.Add(new BagDescriptor(name, contents));
}
var bagNodes = bagDescriptors
.Select(bd => new BagNode {
Name = bd.Name
})
.ToDictionary(b => b.Name, b => b);
foreach (var descriptor in bagDescriptors)
{
var outsideBag = bagNodes[descriptor.Name];
foreach (var content in descriptor.Content)
{
var insideBag = bagNodes[content.Bagname];
var edge = new BagEdge(outsideBag, insideBag, content.Count);
outsideBag.OutgoingEdges.Add(edge);
insideBag.IncomingEdges.Add(edge);
}
}
var workQueue = new Queue <BagNode>();
var initial = bagNodes["shiny gold"];
workQueue.Enqueue(initial);
while (workQueue.Any())
{
var entry = workQueue.Dequeue();
entry.Marked = true;
foreach (var edge in entry.IncomingEdges)
{
if (!edge.ContainingNode.Marked)
{
workQueue.Enqueue(edge.ContainingNode);
}
}
}
var numReached = bagNodes.Count(kvp => kvp.Value.Marked) - 1;
Console.WriteLine(numReached);
var bagCounter = 0;
var contentQueue = new Queue <(BagNode item, int multiplier)>();
contentQueue.Enqueue((initial, 1));
while (contentQueue.Any())
{
var entry = contentQueue.Dequeue();
foreach (var edge in entry.item.OutgoingEdges)
{
bagCounter += edge.Count * entry.multiplier;
contentQueue.Enqueue((edge.ContentNode, entry.multiplier * edge.Count));
}
}
Console.WriteLine(bagCounter);
}
static void Main(string[] args)
{
var lines = File.ReadAllLines("input.txt");
var listOfBags = new List <Bag>();
var baseColours = new List <Bag>();
// Grab all of the distinct bag names to give us a place to start
foreach (var line in lines)
{
var components = line.Split("contain");
var bagColourRaw = components[0];
var bagColour = bagColourRaw.Substring(0, bagColourRaw.Length - 6); // -4 because "bags", 2 for spaces
if (!baseColours.Any(b => b.Colour == bagColour))
{
baseColours.Add(new Bag()
{
Colour = bagColour
});
}
}
// baseColours now has a list of Bags that have all the top level colours
// now need to iterate again to fill up each Bag with the correct contents, using existing Bag refs as
// the content for the bags
// Step through it all again but this time add bags to the list using references saved from above
// Might be able to do this in one loop, but making the assumption that the contents of
// the input file is NOT in order. If it is in order, can do this in one loop
foreach (var line in lines)
{
var components = line.Split("contain");
var bagColourRaw = components[0];
var bagColour = bagColourRaw.Substring(0, bagColourRaw.Length - 6); // -4 because "bags", 2 for spaces
var contentColours = components[1];
var baseBag = baseColours.First(b => b.Colour == bagColour);
if (contentColours.Trim() == "no other bags.")
{
listOfBags.Add(baseBag);
continue;
}
var contentBagsRaw = contentColours.Split(',');
foreach (var content in contentBagsRaw)
{
var cnt = content.Trim();
var pieces = cnt.Split(' ');
var quantity = pieces[0];
var colour = pieces[1] + " " + pieces[2];
var bag = baseColours.First(v => v.Colour == colour);
var bagContent = new BagContent()
{
Bag = bag,
Quantity = Convert.ToInt32(quantity)
};
baseBag.Contents.Add(bagContent);
}
listOfBags.Add(baseBag);
}
// By here the list is fully populate with nodes that reference bags properly
var numberOfBagsContainingAtLeastOne = 0;
foreach (var bag in listOfBags)
{
// Solution for Part 2
if (bag.Colour == "shiny gold")
{
var amountInThisBag = CountBags(bag.Contents);
Console.WriteLine("Shiny gold:" + amountInThisBag);
}
// Solution for Part 1
else
{
var amountInThisBag = CountContent("shiny gold", bag.Contents);
if (amountInThisBag > 0)
{
numberOfBagsContainingAtLeastOne++;
}
}
}
Console.WriteLine(numberOfBagsContainingAtLeastOne);
}
