public override long Part1(string input)
{
var fields = RegexDeserializable.Deserialize <Field>(input).ToArray();
var tickets = Utils.splitLines(input).Where(l => l.Length > 0 && char.IsDigit(l[0])).Select(l => l.Split(',').Select(n => int.Parse(n)).ToArray()).ToArray();
return(tickets.Sum(t => InvalidFieldSum(t, fields)));
}
public override long Part2(string input)
{
var fields = RegexDeserializable.Deserialize <Field>(input).ToArray();
var tickets = Utils.splitLines(input).Where(l => l.Length > 0 && char.IsDigit(l[0])).Select(l => l.Split(',').Select(n => int.Parse(n)).ToArray()).ToArray();
var validTickets = tickets.Where(t => MaybeValid(t, fields)).ToArray();
var assigned = new Queue <int>();
foreach (var field in fields)
{
field.InitIndices(validTickets[0].Length);
foreach (var ticket in validTickets)
{
field.eliminateIndices(ticket, assigned);
}
}
while (assigned.Count > 0)
{
var index = assigned.Dequeue();
foreach (var field in fields)
{
if (field.possibleIndices.Count > 1 && field.possibleIndices.Contains(index))
{
field.possibleIndices.Remove(index);
if (field.possibleIndices.Count == 1)
{
assigned.Enqueue(field.possibleIndices.First());
}
}
}
}
var departureFields = fields.Where(f => f.Name.StartsWith("departure"));
return(departureFields.Aggregate(1L, (a, f) => a * tickets[0][f.possibleIndices.First()]));
}
public override long Part1(string input)
{
var passwords = RegexDeserializable.Deserialize <PasswordPolicy>(input).ToArray();
return(passwords.Count(p => p.IsValid));
}