/// <summary>
/// 探索し、結果を返却します。
/// </summary>
/// <param name="context">フィールド状態</param>
/// <returns>移動方向</returns>
public Direction Search(FieldContext context)
{
StopWatchLogger.StartEventWatch("NegaMaxTemplate.SearchBestValue");
this.Value = this.SearchBestValue(context.DeepCopy(), 1, DefaultAlpha, DefaultBeta);
FileHelper.WriteLine("BestScore:" + this.Value);
StopWatchLogger.StopEventWatch("NegaMaxTemplate.SearchBestValue");
StopWatchLogger.WriteAllEventTimes("./log/eventtime.txt");
return(this.key);
}
/// <summary>
/// 評価値を取得する
/// </summary>
/// <returns></returns>
protected override double GetEvaluate(FieldContext context)
{
StopWatchLogger.StartEventWatch("SearchBestPointer-GetEvaluate");
var score = this.Evaluator.Evaluate(context);
StopWatchLogger.StopEventWatch("SearchBestPointer-GetEvaluate");
FileHelper.WriteLine($"score:{score} direction:{context.OperationDirection}");
return(score * this.GetParity(context));
}
/// <summary>
/// <para>最善手を探索して取得する</para>
/// </summary>
/// <returns></returns>
protected double SearchBestValue(FieldContext context, int depth, double alpha, double beta)
{
// 深さ制限に達した
if (this.IsLimit(depth))
{
return(this.GetEvaluate(context));
}
// 可能な手をすべて生成
var leafList = this.GetAllLeaf(context);
double maxKeyValue = DefaultAlpha;
if (leafList.Count() > 0)
{
// ソート
StopWatchLogger.StartEventWatch("MoveOrdering");
if (this.IsOrdering(depth))
{
leafList = this.MoveOrdering(leafList, context);
}
StopWatchLogger.StopEventWatch("MoveOrdering");
var lastContext = context.DeepCopy();
foreach (Direction leaf in leafList)
{
// 前処理
StopWatchLogger.StartEventWatch("SearchSetUp");
this.SearchSetUp(context, leaf);
StopWatchLogger.StopEventWatch("SearchSetUp");
double value = this.SearchBestValue(context, depth + 1, -beta, -alpha) * -1;
// 後処理
StopWatchLogger.StartEventWatch("SearchTearDown");
//context = this.SearchTearDown(lastContext);
context = lastContext.DeepCopy();
StopWatchLogger.StopEventWatch("SearchTearDown");
// ベータ刈り
if (value >= beta)
{
this.SetKey(leaf, depth);
return(value);
}
if (value > maxKeyValue)
{
// より良い手が見つかった
this.SetKey(leaf, depth);
maxKeyValue = value;
// α値の更新
alpha = Math.Max(alpha, maxKeyValue);
}
}
}
else
{
// ▼パスの場合▼
// 前処理
var lastContext = context.DeepCopy();
this.PassSetUp(context);
maxKeyValue = this.SearchBestValue(context, depth + 1, -beta, -alpha) * -1;
// 後処理
//context = this.PassTearDown(lastContext);
context = lastContext.DeepCopy();
}
Debug.Assert(((maxKeyValue != DefaultAlpha) && (maxKeyValue != DefaultBeta)), "デフォルト値のまま返そうとしています。");
return(maxKeyValue);
}