/// <summary>
/// check whether the position is forbidden
/// </summary>
/// <returns>if it is forbidden ,true;otherwise ,false
/// </returns>
private bool IsFobidden(ref IChessBoard chessBoard,Position point,PieceTypeEnum pieceType)
{
Referee platformCheck = new Referee();
PlayStepResultEnum stepResult=platformCheck.Check(chessBoard, new ChessBoardPoint(point.Row, point.Col), PieceTypeEnum.Black);
//it seems the platform does not check four-three-three
if (stepResult == PlayStepResultEnum.Four_Four ||
stepResult == PlayStepResultEnum.Three_Three ||
stepResult == PlayStepResultEnum.Overline)
{
if (pieceType == PieceTypeEnum.Black)
{
return true;
}
else
{
stepResult = platformCheck.Check(chessBoard, new ChessBoardPoint(point.Row, point.Col), PieceTypeEnum.White);
if (stepResult == PlayStepResultEnum.Four_Four ||
stepResult == PlayStepResultEnum.Three_Three||
stepResult==PlayStepResultEnum.Win)
{
return false;
}
}
}
return false;
}
/// <summary>
/// update score table
/// </summary>
/// <param name="scoreTable"></param>
/// <param name="col">columnIndex of new joined chess</param>
/// <param name="row">rowIndex of new joined chess</param>
private void UpdateScoreTable(ref IChessBoard chessBoard, Position pos,PieceTypeEnum pieceType)
{
//could not happen
/* if (chessBoard.GetPointState(pos.Col,pos.Row)!=PointStateEnum.Blank)
{
return;
}
*/
#region ---partial board
//get all the 32 piece states surrounding this position
ExtendedPointStateEnum[,] pointState=new ExtendedPointStateEnum[4,9];
int row,col;
//horizontal
for (col = pos.Col - 4; col < pos.Col + 5;col++)
{
if (col<0||col>14)
{
pointState[0,col-pos.Col+4]=ExtendedPointStateEnum.Virtual;
}
else
{
pointState[0, col - pos.Col + 4] = (ExtendedPointStateEnum)chessBoard.GetPointState(pos.Row,col);
}
}
//vertical
for (row = pos.Row - 4; row < pos.Row + 5;row++ )
{
if (row<0||row>14)
{
pointState[1, row - pos.Row + 4] = ExtendedPointStateEnum.Virtual;
}
else
{
pointState[1, row - pos.Row + 4] = (ExtendedPointStateEnum)chessBoard.GetPointState(row,pos.Col);
}
}
//backslash
for (row = pos.Row - 4, col = pos.Col - 4; row < pos.Row + 5;row++,col++ )
{
if (row < 0 || row > 14 || col < 0 || col > 14)
{
pointState[2, row - pos.Row + 4] = ExtendedPointStateEnum.Virtual;
}
else
{
pointState[2, row - pos.Row + 4] = (ExtendedPointStateEnum)chessBoard.GetPointState(row, col);
}
}
//slash
for (row = pos.Row + 4, col = pos.Col - 4; row > pos.Row - 5; row--, col++)
{
if (row < 0 || row > 14 || col < 0 || col > 14)
{
pointState[3, col - pos.Col + 4] = ExtendedPointStateEnum.Virtual;
}
else
{
pointState[3, col - pos.Col + 4] = (ExtendedPointStateEnum)chessBoard.GetPointState(col, col);
}
}
//assume the center of partial board is empty
for (int m = 0; m < 4;m++ )
{
pointState[m, 4] = ExtendedPointStateEnum.Blank;
}
#endregion
#region ---recognize formerTuples
//recognize types of all the 20 Tuples .
TupleType[,] formerTuples = new TupleType[4, 5];
TupleType[,] changedTuples = new TupleType[4, 5];
int white, black, blank;
for (int i = 0; i < 4;i++ )
{
int start=0;
int finish = 0;
//deal with virtual tuples from front
for (int j = 0; j < 4;j++ )
{
if (pointState[i,j]==ExtendedPointStateEnum.Virtual)
{
changedTuples[i,j] = formerTuples[i, j] = TupleType.Virtual;
}
else
{
start = j;
break;//jump inner layer loop
}
}
//deal with virtual tuples from back
for (int j = 8; j >= 5;j-- )
{
if (pointState[i, j] == ExtendedPointStateEnum.Virtual)
{
changedTuples[i, j-4] = formerTuples[i, j - 4] = TupleType.Virtual;
}
else
{
finish = j;
break;//jump inner layer loop
}
}
white = black = blank = 0;
//start recognize general tuples,deal with first four points
for (int j = start; j <start+4;j++ )
{
if (pointState[i, j] == ExtendedPointStateEnum.Blank)
{
blank++;
}
else if (pointState[i, j] == ExtendedPointStateEnum.Black)
{
black++;
}
else if (pointState[i, j] == ExtendedPointStateEnum.White)
{
white++;
}
}
//tuples recognition sliding
for (int j = start + 4; j <= finish;j++ )
{
if (pointState[i, j] == ExtendedPointStateEnum.Blank)
{
blank++;
}
else if (pointState[i, j] == ExtendedPointStateEnum.Black)
{
black++;
}
else if (pointState[i, j] == ExtendedPointStateEnum.White)
{
white++;
}
//deal with formerTuples
if (black > 0 && white > 0)
{
formerTuples[i, j - 4] = TupleType.Polluted;
}
else if (black == 0 && white == 0)
{
formerTuples[i, j - 4] = TupleType.Blank;
}
else if (black == 0)
{
formerTuples[i, j - 4] = (TupleType)(white + 4);
}
else
{
formerTuples[i, j - 4] = (TupleType)black;
}
//deal with changedTuples,increase for change
if (pieceType==PieceTypeEnum.Black)
{
black++;
}
else
{
white++;
}
//recognize
if (black > 0 && white > 0)
{
changedTuples[i, j - 4] = TupleType.Polluted;
}
else if (black == 0 && white == 0)
{
changedTuples[i, j - 4] = TupleType.Blank;
}
else if (black == 0)
{
changedTuples[i, j - 4] = (TupleType)(white + 4);
}
else
{
changedTuples[i, j - 4] = (TupleType)black;
}
//deal with changedTuples,decrease
if (pieceType == PieceTypeEnum.Black)
{
black--;
}
else
{
white--;
}
//slide to next tuple ,so the first of current tuple should be dropped
if (pointState[i, j-4] == ExtendedPointStateEnum.Blank)
{
blank--;
}
else if (pointState[i, j-4] == ExtendedPointStateEnum.Black)
{
black--;
}
else if (pointState[i, j-4] == ExtendedPointStateEnum.White)
{
white--;
}
}
}
#endregion
#region ---update scores of correlative points
//score changed caused by this chess
int[,] changedScore = new int[4, 5];
for (int i = 0; i < 4;i++ )
{
for (int j = 0; j < 5;j++ )
{
int score=tupleScoreTable[(int)changedTuples[i,j]]-tupleScoreTable[(int)formerTuples[i,j]];
changedScore[i, j] = score;
}
}
//internal calculation
int[,] changedScoreSum = new int[4, 9];
for (int i = 0; i < 4;i++ )
{
for (int j = 0; j < 4;j++ )
{
int sum=0;
for (int m=0;m<=j;m++)
{
sum+=changedScore[i,m];
}
changedScoreSum[i,j]=sum;
}
for (int j = 8; j > 4;j-- )
{
int sum = 0;
for (int m=8;m>=j;m--)
{
sum += changedScore[i, m-4];
}
changedScoreSum[i, j] = sum;
}
}
//update center point,occupied point's score is 0
scoreTable[pos.Col, pos.Row] = 0;
//update general points
//horizontal
for (col = (pos.Col >= 4?pos.Col-4:0);
col <= (pos.Col <=10?pos.Col+4:14);
col++)
{
if (scoreTable[col,pos.Row]!=0)//not occupied
{
scoreTable[col, pos.Row] += changedScoreSum[0, col - pos.Col + 4];
if (scoreTable[col, pos.Row] < 0)
{
scoreTable[col, pos.Row] = 0;
}
}
}
//vertical
for (row = (pos.Row >= 4 ? pos.Row - 4 : 0);
row <= (pos.Row <= 10 ? pos.Row + 4 : 14);
row++)
{
if (scoreTable[pos.Col, row] != 0)//not occupied
{
scoreTable[pos.Col, row] += changedScoreSum[1, row - pos.Row + 4];
if (scoreTable[pos.Col, row] < 0)
{
scoreTable[pos.Col, row] = 0;
}
}
}
//backslash
for (col = (pos.Col >= 4 ? pos.Col - 4 : 0),
row = (pos.Row >= 4 ? pos.Row - 4 : 0);
col <= (pos.Col <= 10 ? pos.Col + 4 : 14) &&
row <= (pos.Row <= 10 ? pos.Row + 4 : 14);
col++,row++)
{
if (scoreTable[col, row] != 0)//not occupied
{
scoreTable[col, row] += changedScoreSum[2, row - pos.Row + 4];
if (scoreTable[col, row]<0)
{
scoreTable[col, row] = 0;
}
}
}
//slash
for (col = (pos.Col >= 4 ? pos.Col - 4 : 0),
row = (pos.Row <= 10 ? pos.Row + 4 : 14);
col <= (pos.Col <= 10 ? pos.Col + 4 : 14) &&
row >= (pos.Row >= 4 ? pos.Row - 4 : 0);
col++, row--)
{
if (scoreTable[col, row] != 0)//not occupied
{
scoreTable[col, row] += changedScoreSum[3, col - pos.Col + 4];
if (scoreTable[col, row] < 0)
{
scoreTable[col, row] = 0;
}
}
}
#endregion
}
public ChessBoardPoint GetNextStep(IChessBoard chessBoard, PieceTypeEnum pieceType, int stepIndex, PlayStep? prevStep)
{
int[] tupleScoreTable = new int[11] { 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
//initialize tuple score table
if (stepIndex % 2 == 0)//even step is first hand,i.e. the black side
{
if (stepIndex == 0)
{
return ChessBoardPoint.TENGEN;
}
else if(stepIndex==2)
{
Position[][] classicalOpen = new Position[8][];
//0:white is on left side of Tengen
classicalOpen[0]=new Position[21]{
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position()};
//1:white is on up side of Tengen
classicalOpen[1]=new Position[21]{
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position()};
//2:white is on right side of Tengen
classicalOpen[2]=new Position[21]{
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position()};
//3:white is on bottom side of Tengen
classicalOpen[3]=new Position[21]{
new Position(8,8),new Position(9,7),new Position(7,8),new Position(7,9),
new Position(8,9),new Position(6,9),new Position(5,8),new Position(6,8),
new Position(6,7),new Position(5,7),new Position(9,9),new Position(5,5),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position()};
//4:white is on topleft corner of Tengen
classicalOpen[4]=new Position[25]{
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position()};
//5:white is on topright corner of Tengen
classicalOpen[5]=new Position[25]{
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position()};
//6:white is on bottomright corner of Tengen
classicalOpen[6]=new Position[25]{
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position()};
//7:white is on bottomleft corner of Tengen
classicalOpen[7] = new Position[25]{
new Position(6,6),new Position(7,5),new Position(7,6),new Position(6,5),
new Position(8,5),new Position(6,8),new Position(9,5),new Position(7,9),
new Position(5,5),new Position(5,6),new Position(7,8),new Position(5,8),
new Position(5,9),new Position(8,5),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position(),new Position(),new Position(),new Position(),
new Position()};
Position whiteFirst = new Position(14-prevStep.Value.Location.RowIndex, prevStep.Value.Location.ColumnIndex);
switch ()
{
case :
break;
}
}
tupleScoreTable[1] = 35;
tupleScoreTable[2] = 800;
tupleScoreTable[3] = 15000;
tupleScoreTable[4] = 800000;
tupleScoreTable[5] = 15;
tupleScoreTable[6] = 400;
tupleScoreTable[7] = 1800;
tupleScoreTable[8] = 100000;
}
else//odd step is back hand,i.e. the white side
{
tupleScoreTable[1] = 15;
tupleScoreTable[2] = 400;
tupleScoreTable[3] = 1800;
tupleScoreTable[4] = 100000;
tupleScoreTable[5] = 35;
tupleScoreTable[6] = 800;
tupleScoreTable[7] = 15000;
tupleScoreTable[8] = 800000;
}
//extended board,with virtual points
ExtendedPointStateEnum[,] exPointStates = new ExtendedPointStateEnum[23, 23];
for (int row = 0; row < 23; row++)
{
for (int col = 0; col < 23; col++)
{
if (row < 4 || row > 18 || col < 4 || col > 18)
{
exPointStates[row, col] = ExtendedPointStateEnum.Virtual;
}
else
{
exPointStates[row, col] = (ExtendedPointStateEnum)chessBoard.GetPointState(14 - (row - 4), col - 4);
}
}
}
int[,] scoreTable = new int[15, 15];
/// <summary>calculate type of every tuple</summary>
/// <description>In order to give a clear train of thought,
/// I used an intuitionistic method to do this work.
/// But this results in not efficient.
/// Every tuple is calculated for twice.
/// But it's easy to modify it:two ends of a tuple own the same tuple
/// I'll modify it in next version ,where efficiency becomes bottleneck.
/// </description>
//every point indexs 8 tuples around it
TupleType[, ,] tupleTable = new TupleType[15, 15, 8];
for (int row = 4; row < 19; row++)
{
for (int col = 4; col < 19; col++)
{
int[] white = new int[8];//white points in a tuple
int[] black = new int[8];//black points in a tuple
#region ---check tuples of every direction
//left ,index 0
for (int i = 0; i < 5; i++)
{
if (exPointStates[row, col - i] == ExtendedPointStateEnum.Virtual)
{
tupleTable[row - 4, col - 4, 0] = TupleType.Virtual;
break;
}
else if (exPointStates[row, col - i] == ExtendedPointStateEnum.Black)
{
black[0]++;
}
else if (exPointStates[row, col - i] == ExtendedPointStateEnum.White)
{
white[0]++;
}
}
//top left,index 1
for (int i = 0; i < 5; i++)
{
if (exPointStates[row - i, col - i] == ExtendedPointStateEnum.Virtual)
{
tupleTable[row - 4, col - 4, 1] = TupleType.Virtual;
break;
}
else if (exPointStates[row - i, col - i] == ExtendedPointStateEnum.Black)
{
black[1]++;
}
else if (exPointStates[row - i, col - i] == ExtendedPointStateEnum.White)
{
white[1]++;
}
}
//up ,index 2
for (int i = 0; i < 5; i++)
{
if (exPointStates[row - i, col] == ExtendedPointStateEnum.Virtual)
{
tupleTable[row - 4, col - 4, 2] = TupleType.Virtual;
break;
}
else if (exPointStates[row - i, col] == ExtendedPointStateEnum.Black)
{
black[2]++;
}
else if (exPointStates[row - i, col] == ExtendedPointStateEnum.White)
{
white[2]++;
}
}
//top right,index 3
for (int i = 0; i < 5; i++)
{
if (exPointStates[row - i, col + i] == ExtendedPointStateEnum.Virtual)
{
tupleTable[row - 4, col - 4, 3] = TupleType.Virtual;
break;
}
else if (exPointStates[row - i, col + i] == ExtendedPointStateEnum.Black)
{
black[3]++;
}
else if (exPointStates[row - i, col + i] == ExtendedPointStateEnum.White)
{
white[3]++;
}
}
//right,index 4
for (int i = 0; i < 5; i++)
{
if (exPointStates[row, col + i] == ExtendedPointStateEnum.Virtual)
{
tupleTable[row - 4, col - 4, 4] = TupleType.Virtual;
break;
}
else if (exPointStates[row, col + i] == ExtendedPointStateEnum.Black)
{
black[4]++;
}
else if (exPointStates[row, col + i] == ExtendedPointStateEnum.White)
{
white[4]++;
}
}
//bottom right,index 5
for (int i = 0; i < 5; i++)
{
if (exPointStates[row + i, col + i] == ExtendedPointStateEnum.Virtual)
{
tupleTable[row - 4, col - 4, 5] = TupleType.Virtual;
break;
}
else if (exPointStates[row + i, col + i] == ExtendedPointStateEnum.Black)
{
black[5]++;
}
else if (exPointStates[row + i, col + i] == ExtendedPointStateEnum.White)
{
white[5]++;
}
}
//bottom,index 6
for (int i = 0; i < 5; i++)
{
if (exPointStates[row + i, col] == ExtendedPointStateEnum.Virtual)
{
tupleTable[row - 4, col - 4, 6] = TupleType.Virtual;
break;
}
else if (exPointStates[row + i, col] == ExtendedPointStateEnum.Black)
{
black[6]++;
}
else if (exPointStates[row + i, col] == ExtendedPointStateEnum.White)
{
white[6]++;
}
}
//bottom left,index 7
for (int i = 0; i < 5; i++)
{
if (exPointStates[row + i, col - i] == ExtendedPointStateEnum.Virtual)
{
tupleTable[row - 4, col - 4, 7] = TupleType.Virtual;
break;
}
else if (exPointStates[row + i, col - i] == ExtendedPointStateEnum.Black)
{
black[7]++;
}
else if (exPointStates[row + i, col - i] == ExtendedPointStateEnum.White)
{
white[7]++;
}
}
#endregion //check tuples of every direction
//decide tuple type
for (int i = 0; i < 8; i++)
{
//already assigned
if (tupleTable[row - 4, col - 4, i] == TupleType.Virtual)
{
continue;
}
if (white[i] > 0 && black[i] > 0)
{
tupleTable[row - 4, col - 4, i] = TupleType.Polluted;
}
else if (white[i] == 0 && black[i] == 0)
{
tupleTable[row - 4, col - 4, i] = TupleType.Blank;
}
else if (white[i] == 0)
{
tupleTable[row - 4, col - 4, i] = (TupleType)black[i];
}
else
{
tupleTable[row - 4, col - 4, i] = (TupleType)(white[i] + 4);
}
}
}
}
#region ---scoreTable calculate
//calculate score table . using symmetry
//top left corner
for (int row = 0; row < 8; row++)
{
for (int col = 0; col < 8; col++)
{
if (exPointStates[row + 4, col + 4] != ExtendedPointStateEnum.Blank)
{
//this situation has been considered
//scoreTable[row,col]=0;
continue;
}
for (int m = 0; m < 5; m++)
{
if (row >= m)//top right
{
scoreTable[row, col] += tupleScoreTable[(int)tupleTable[row - m, col + m, 7]];
}
scoreTable[row, col] += tupleScoreTable[(int)tupleTable[row + m, col, 2]];//bottom
scoreTable[row, col] += tupleScoreTable[(int)tupleTable[row + m, col + m, 1]];//bottom right
scoreTable[row, col] += tupleScoreTable[(int)tupleTable[row, col + m, 0]];//right
}
}
}
//top right corner
for (int row = 0; row < 8; row++)
{
for (int col = 8; col < 15; col++)
{
if (exPointStates[row + 4, col + 4] != ExtendedPointStateEnum.Blank)
{
//this situation has been considered
//scoreTable[row,col]=0;
continue;
}
for (int m = 0; m < 5; m++)
{
if (row >= m)//top left
{
scoreTable[row, col] += tupleScoreTable[(int)tupleTable[row - m, col - m, 5]];
}
scoreTable[row, col] += tupleScoreTable[(int)tupleTable[row + m, col, 2]];//bottom
scoreTable[row, col] += tupleScoreTable[(int)tupleTable[row + m, col - m, 3]];//bottom left
scoreTable[row, col] += tupleScoreTable[(int)tupleTable[row, col - m, 4]];//left
}
}
}
//bottom left corner
for (int row = 8; row < 15; row++)
{
for (int col = 0; col < 8; col++)
{
if (exPointStates[row + 4, col + 4] != ExtendedPointStateEnum.Blank)
{
//this situation has been considered
//scoreTable[row,col]=0;
continue;
}
for (int m = 0; m < 5; m++)
{
if (row + m < 15)//bottom right
{
scoreTable[row, col] += tupleScoreTable[(int)tupleTable[row + m, col + m, 1]];
}
scoreTable[row, col] += tupleScoreTable[(int)tupleTable[row - m, col, 6]];//top
scoreTable[row, col] += tupleScoreTable[(int)tupleTable[row - m, col + m, 7]];//top right
scoreTable[row, col] += tupleScoreTable[(int)tupleTable[row, col + m, 0]];//right
}
}
}
//bottom right corner
for (int row = 8; row < 15; row++)
{
for (int col = 8; col < 15; col++)
{
if (exPointStates[row + 4, col + 4] != ExtendedPointStateEnum.Blank)
{
//this situation has been considered
//scoreTable[row,col]=0;
continue;
}
for (int m = 0; m < 5; m++)
{
if (row + m < 15)//bottom left
{
scoreTable[row, col] += tupleScoreTable[(int)tupleTable[row + m, col - m, 3]];
}
scoreTable[row, col] += tupleScoreTable[(int)tupleTable[row - m, col, 6]];//top
scoreTable[row, col] += tupleScoreTable[(int)tupleTable[row - m, col - m, 5]];//top left
scoreTable[row, col] += tupleScoreTable[(int)tupleTable[row, col - m, 4]];//left
}
}
}
#endregion //scoreTable
//select best position
List<Position> bestList = new List<Position>();
//select first valid point
Position first = new Position(0, 0);
//all the point is forbidden.connot happen
//while (IsFobidden(first))
//{
// while (IsFobidden(first))
// {
// if (first.Col<14)
// {
// first.Col++;
// }
// else
// {
// break;
// }
// }
// if (first.Row<14)
// {
// first.Row++;
// }
// else
// {
// break;
// }
//}
while (IsFobidden(ref chessBoard, first, pieceType))
{
if (first.Col < 14)
{
first.Col++;
}
else if (first.Row < 14)
{
first.Row++;
first.Col = 0;
}
else
{
return new ChessBoardPoint(-1, -1);
}
}
bestList.Add(first);
Referee checkWin = new Referee();
//select best points
for (int row = 0; row < 15; row++)
{
for (int col = 0; col < 15; col++)
{
if (scoreTable[row, col] > scoreTable[bestList[0].Row, bestList[0].Col])
{
Position best = new Position(row, col);
if (!IsFobidden(ref chessBoard, best, pieceType))
{
bestList.Clear();
bestList.Add(best);
}
}
else if (scoreTable[row, col] == scoreTable[bestList[0].Row, bestList[0].Col])
{
Position best = new Position(row, col);
if (!IsFobidden(ref chessBoard, best, pieceType))
{
bestList.Add(best);
}
}
}
}
//there is no best .connot happen
if (bestList.Count == 0)
{
return new ChessBoardPoint(-1, -1);
}
Position ret = bestList[(new Random()).Next(bestList.Count)];
return new ChessBoardPoint(14 - ret.Row, ret.Col);
}
//is forbidden
private bool IsFobidden(ref IChessBoard chessBoard, Position point, PieceTypeEnum pieceType)
{
Referee platformCheck = new Referee();
PlayStepResultEnum stepResult = platformCheck.Check(chessBoard, new ChessBoardPoint(14 - point.Row, point.Col), PieceTypeEnum.Black);
//it seems the platform does not check four-three-three
if (stepResult == PlayStepResultEnum.Four_Four ||
stepResult == PlayStepResultEnum.Three_Three ||
stepResult == PlayStepResultEnum.Overline)
{
if (pieceType == PieceTypeEnum.Black)
{
return true;
}
else
{
//white priority vs. black forbidden
//if this position is black-forbidden,generally white should not be put here
//but if is advantaged enough for white,it should
if (PlayStepResultEnum.Win == platformCheck.Check(chessBoard, new ChessBoardPoint(14 - point.Row, point.Col), PieceTypeEnum.White))
{
return false;
}
else
{
return true;
}
}
}
return false;
}
/// <summary>
/// 获得当前五子棋策略的下一步落棋位置。
/// </summary>
/// <param name="chessBoard">五子棋棋盘对象。</param>
/// <param name="pieceType">棋子的类型。</param>
/// <param name="stepIndex">下一步落子操作的序号。</param>
/// <param name="prevStep">包含对方上一步落子操作信息的走步对象。</param>
/// <returns>下一步落棋的位置。</returns>
public ChessBoardPoint GetNextStep(IChessBoard chessBoard, PieceTypeEnum pieceType, int stepIndex, PlayStep? prevStep)
{
//change the frame of axes to our( |_ to |- )
//判断是否为黑方的第一手棋
if (stepIndex == 0&&pieceType == PieceTypeEnum.Black )
{
// update score table
UpdateScoreTable(ref chessBoard,new Position(7,7),PieceTypeEnum.Black);
//如果是黑方的第一手棋，则总是返回天元
return ChessBoardPoint.TENGEN;
}else if(stepIndex==1&&pieceType==PieceTypeEnum.White){
//change scoreTable to defensive order
for (int i = 1; i < 5;i++ )
{
int tmp = tupleScoreTable[i];
tupleScoreTable[i] = tupleScoreTable[i + 4];
tupleScoreTable[i + 4] = tmp;
}
}
Position preStepPos = new Position(14 - prevStep.Value.Location.RowIndex, prevStep.Value.Location.ColumnIndex);
//update score table for changes caused by previous step
UpdateScoreTable(ref chessBoard, preStepPos,prevStep.Value.PieceType);
// position to play chess
Position bestPos = FindBestPos(ref chessBoard, prevStep.Value.PieceType);
//update score table for changes caused by this step
UpdateScoreTable(ref chessBoard,bestPos,prevStep.Value.PieceType==PieceTypeEnum.Black?PieceTypeEnum.White:PieceTypeEnum.Black);
return new ChessBoardPoint(14-bestPos.Row,bestPos.Col);
}