private static void Part2()
{
// Count the number of bags inside our bag rule
BagRule ourBagRule = allBagRules.Find(r => r.Name == ourBagColour);
long totalBagsInRule = BagsWithinRule(ourBagRule, 1);
Console.WriteLine($"\nPart 2: {totalBagsInRule}");
}
private static long BagsWithinRule(BagRule rule, int quantity)
{
long result = rule.Quantity;
foreach (var bag in rule.BagContents)
{
result += quantity * bag.Quantity;
BagRule thisRule = allBagRules.Find(r => r.Name == bag.Name);
result += quantity * BagsWithinRule(thisRule, bag.Quantity);
}
return(result);
}
public static int CanHoldBagColor(BagRule[] allRules, BagRule currentRule, Color colorToCheck)
{
if (currentRule.AllowedChildBags.Any(b => b.BagColor == colorToCheck))
{
return(1);
}
return(currentRule
.AllowedChildBags
.Aggregate(
0,
(acc, cr) => acc + CanHoldBagColor(allRules, allRules.Single(r => r.BagColor == cr.BagColor), colorToCheck)
));
}
public static int CountContainedBags
(
IReadOnlyDictionary <Color, BagRule> allRules,
BagRule currentRule
)
{
int childSum =
currentRule
.AllowedChildBags
.SelectMany(cr => Enumerable.Repeat(allRules[cr.BagColor], cr.Amount))
.Select(r => CountContainedBags(allRules, r) + 1)
.Sum();
return(childSum);
}
private static bool RuleContainsBag(BagRule rule, string bagName)
{
bool result = false;
if (rule.Name == bagName)
{
return(true);
}
foreach (var bag in rule.BagContents)
{
BagRule thisRule = allBagRules.Find(r => r.Name == bag.Name);
result = RuleContainsBag(thisRule, bagName);
if (result)
{
return(true);
}
}
return(result);
}
private static void CreateBagRules()
{
allBagRules = new List <BagRule>();
foreach (var line in input)
{
// Remove words bag and bags and Replace 'contains' with ":"
string newLine = line.Replace(".", "").Replace("bags", "bag").Replace("bag", "").Replace("contain", ":");
//Console.WriteLine($"\n{newLine}");
// Split on ':'
string[] thisLine = newLine.Split(':');
string thisColour = thisLine[0].Trim();
// Split on ','
string[] contains = thisLine[1].Split(',');
BagRule newBag = new BagRule();
newBag.Name = thisColour;
//Console.WriteLine($"{newBag.Name}");
foreach (var bag in contains)
{
string thisContents = bag.Trim();
if (thisContents != "no other")
{
string quantity = thisContents.Substring(0, thisContents.IndexOf(' ')).Trim();
string name = thisContents.Substring(thisContents.IndexOf(' ')).Trim();
newBag.BagContents.Add(new BagRule(name, quantity));
//Console.WriteLine($"{quantity} - {name}");
}
}
allBagRules.Add(newBag);
}
}