public SolverState(Nonogram nonogram, TimeSpan?timeout, bool useMultipleCores, CancellationTokenSource cancellationTokenSource)
{
Nonogram = nonogram ?? throw new ArgumentNullException(nameof(nonogram));
_cancellationTokenSource = cancellationTokenSource ?? throw new ArgumentNullException(nameof(cancellationTokenSource));
CancellationToken = _cancellationTokenSource.Token;
Timeout = timeout;
UseMultipleCores = useMultipleCores;
Stopwatch = new Stopwatch();
Tiles = new TilesCollection(nonogram.RowCount, nonogram.ColumnCount);
}
/// <summary>
/// Try to solve the given <see cref="Nonogram"/>.
/// </summary>
/// <param name="nonogram">The <see cref="Nonogram"/> to solve.</param>
/// <param name="timeout">If given, we'll abort our search for a solution if it takes too long.</param>
/// <param name="cancellationTokenSource">
/// If you want to control cancellation yourself, pass in a <see cref="CancellationTokenSource"/>.
/// Note that if you also set a <paramref name="timeout"/>, the Solver will call <see cref="CancellationTokenSource.Cancel"/> if the timeout expires.
/// </param>
/// <param name="useMultipleCores">If set to true, we try to parallelize solving the <see cref="Nonogram"/>, otherwise we only use 1 CPU core.</param>
/// <returns>A <see cref="Solution"/> to the <see cref="Nonogram"/>, although it may not be a successful one.</returns>
public static Solution Solve(Nonogram nonogram, TimeSpan?timeout = null, CancellationTokenSource cancellationTokenSource = null, bool useMultipleCores = true)
{
bool disposeCts = cancellationTokenSource == null;
try
{
cancellationTokenSource = cancellationTokenSource ?? new CancellationTokenSource();
var state = new SolverState(nonogram, timeout, useMultipleCores, cancellationTokenSource);
if (!state.PopulatePermutations())
{
return(state.CreateSolution(SolveResult.Cancelled));
}
var stepResult = ProcessStepResult.KeepGoing;
while (stepResult == ProcessStepResult.KeepGoing)
{
state.Stopwatch.Restart();
stepResult = Step(state.RowPermutations, state.ColumnPermutations, state.CancellationToken);
state.StepCount++;
if (stepResult == ProcessStepResult.Unsolvable)
{
return(state.CreateSolution(SolveResult.Unsolvable));
}
state.Stopwatch.Stop();
state.UpdateElapsed();
if (state.HasHitTimeout || state.CancellationToken.IsCancellationRequested)
{
state.CancelToken();
return(state.CreateSolution(SolveResult.Cancelled));
}
}
return(state.CreateSolution(SolveResult.Success));
}
finally
{
if (disposeCts && cancellationTokenSource != null)
{
cancellationTokenSource.Dispose();
}
}
}