// If the citizens are put in 2 lines, each which can see the other line, but not themselves, they need to determine which hats to guess
// based on the set of hats in the other line. So there are 2 signals being sent, 1 by each line. There are 2 responses, 1 by each line.
//
// So we need to create a signal for the smaller line to send to the larger line, such that it's possible to create a signal that the larger
// line can send.
//
// So this takes in the code from the smaller line to the larger line and computes the code that the larger line needs to return
public OneWayCode GetSecondCodeFromFirstCode(OneWayCode code, int numDifferentColors)
{
var numPeopleInLineSendingFirstCode = code.OneWaySignals.First().Signal.Assignment.Length;
var numPeopleInLineSendingSecondCode = code.OneWaySignals.First().Response.Assignment.Length;
var keySetOfFirstCode = this.GenerateAllPossibleHatAssignments(
numPeopleInLineSendingFirstCode,
numDifferentColors,
1);
var keySetOfSecondCode = this.GenerateAllPossibleHatAssignments(
numPeopleInLineSendingSecondCode,
numDifferentColors,
1 + numPeopleInLineSendingFirstCode);
var signals = new List<OneWaySignal>();
foreach(var signal in keySetOfSecondCode)
{
var response = this.GetResponseFromSignal(signal, code, keySetOfFirstCode);
var signalCopy = signal.DeepCopyHatAssignment();
var responseCopy = response?.DeepCopyHatAssignment();
signals.Add(new OneWaySignal
{
Signal = signalCopy,
Response = responseCopy
});
}
return new OneWayCode { OneWaySignals = signals };
}
public HatAssignment GetResponseFromSignal(HatAssignment signal, OneWayCode code, List<HatAssignment> keySetOfFirstCode)
{
var responsesToMatch = new List<HatAssignment>();
foreach (var oldSignal in code.OneWaySignals)
{
if (!this.PairContainsAtLeastOneMatchingHat(signal, oldSignal.Response))
{
responsesToMatch.Add(oldSignal.Signal);
}
}
foreach (var possibleResponse in keySetOfFirstCode)
{
if (responsesToMatch.All(r => this.PairContainsAtLeastOneMatchingHat(possibleResponse, r)))
{
return possibleResponse;
}
}
return null;
}
