private static async ValueTask <int> CalculateOutputSignalWithFeedbackAsync(IEnumerable <int> phaseSettingInputs, int[] program)
{
var channel = await Task.WhenAll(phaseSettingInputs.Select(CreateAmplifierInputChannel));
var count = channel.Length;
var amp = new Task[count];
for (int i = 0; i < count; ++i)
{
// get this amplifier's input
var input = channel[i];
// connect the output to the next amplifier's input
var output = channel[(i + 1) % channel.Length];
// run the program
amp[i] = IntcodeMachine.RunProgramAsync(program, input.Reader, output.Writer);
}
// send initial input to the first amp
await channel.First().Writer.WriteAsync(0);
// wait for all of the programs to finish
await Task.WhenAll(amp);
// retrieve the final output from the input of the first amp
return(await channel.First().Reader.ReadAsync());
}
public static async Task RunProgramAsync(
int[] program, ChannelReader <int> input, ChannelWriter <int> output,
CancellationToken cancellationToken = default, bool complete = true)
{
try
{
var vm = new IntcodeMachine(program, input, output);
await vm.StepUntilHalted(cancellationToken);
}
catch (Exception ex)
{
if (complete)
{
output.TryComplete(ex);
}
}
finally
{
if (complete)
{
output.TryComplete();
}
}
}
private static int CalculateOutputSignal(IEnumerable <int> phaseSettingInputs, int[] program)
=> phaseSettingInputs.Aggregate(0, (prev, phase) => IntcodeMachine.RunProgram(program, new[] { phase, prev }).Single());