C++ (Cpp) PositionStruct::NullMove Beispiele

Beispiel #1

Datei: search.cpp Projekt: peteryuanpan/lazyboy

// 零窗口搜索
int SearchCut ( int depth, int beta, bool bNoNull = false ) {
	int mv, vl;
	int bmv = 0;
	int bvl = - MATE_VALUE;
	MoveSortStruct mvsort;

	if ( TimeOut() ) { // 超时
		return bvl;
	}

	// 无害裁剪
	vl = HarmlessPruning ();
	if ( vl > - MATE_VALUE ) {
		return vl;
	}

	// 置换裁剪
	vl = QueryValueInHashTable ( depth, beta - 1, beta );
	if ( vl > - MATE_VALUE ) {
		return vl;
	}

	// 达到极限深度
	if ( depth <= 0 ) {
		return SearchQuiesc ( beta - 1, beta );
	}

	// 空着裁剪 : 大切に
	if ( !bNoNull && pos.checked == false && pos.NullOkay() ) {
		pos.NullMove ();
		vl = - SearchCut ( depth - NULL_DEPTH - 1, beta, true );
		pos.UndoNullMove ();
		if ( TimeOut() ) { // 超时
			return bvl;
		}

		if ( vl >= beta ) {
			if ( pos.NullSafe() ) {
				InsertInfoToHashTable ( MAX(depth, NULL_DEPTH + 1), 0, vl, HASH_TYPE_BETA );
				return vl;
			}
			else if ( SearchCut(depth - NULL_DEPTH, beta, true) >= beta ) {
				InsertInfoToHashTable ( MAX(depth, NULL_DEPTH), 0, vl, HASH_TYPE_BETA );
				return vl;
			}
		}
	}

	// 生成着法
	int nMoveNum = mvsort.InitMove ();
	Search.nNode ++;

	// 大搜索
	while ( (mv = mvsort.NextMove()) != 0 ) {
		pos.MakeMove ( mv );
		int newDepth = ( pos.checked || nMoveNum == 1 ) ? depth : depth - 1;
		vl = - SearchCut ( newDepth, 1 - beta );
		pos.UndoMakeMove ();

		if ( TimeOut() ) { // 超时
			return bvl;
		}

		// 边界
		if ( vl > bvl ) {
			bvl = vl;
			bmv = mv;
			if ( bvl >= beta ) {
				Search.nBeta ++;
				InsertInfoToHashTable ( depth, bmv, bvl, HASH_TYPE_BETA );
				InsertHistoryTable ( bmv, depth );
				return bvl;
			}
		}
	}

	// 最后
	InsertInfoToHashTable ( depth, bmv, bvl, HASH_TYPE_ALPHA );
	return bvl;
}