public override void Move(Board b)
{
{
//Create a new game state for the root of the state space
GameState gameState = new GameState(GameState.State.initial, b, this, null, cell, true);
//Set the state as the root
MiniMaxTree m = new MiniMaxTree(gameState);
//Find children states if they exist
m.GenerateStates(gameState, 4, true);
//The value returned by the recursive minimax function
int value = m.MiniMax(gameState, 4, true);
cell = null;
foreach(GameState child in gameState.GetChildren())
{
if (child.GetHeuristicValue() == value)
{
cell = child.GetCell();
}
}
//Set the cell on the playing board
b.getCell(cell.getRow(), cell.getColumn()).setState((int)cell.getState());
//if a row exists above this cell, make it playable
if (cell.getRow() != 0)
{
b.getCell(cell.getRow() - 1, cell.getColumn()).isPlayable(true);
}
//Test if the game is over
if(MiniMaxTree.TerminalTest(cell))
{
b.printBoard();
Console.WriteLine("GameOver: " + this.getColorToString() + " wins");
b.isGameOver(true);
}
moveCount++;
}
}
public int MiniMax(GameState gs, int depth, Boolean maxPlayer)
{
//base case
if (depth == 0 || gs.GetState().Equals(GameState.State.terminal))
{
return FindHeuristicValue(gs);
}
if(maxPlayer)
{
int bestValue = MIN_VALUE;
foreach(GameState child in gs.GetChildren())
{
int value = MiniMax(child, depth - 1, false);
if (value.CompareTo(bestValue) > 0)
{
gs.SetHeuristicValue(value);
bestValue = value;
}
}
return bestValue;
}
else
{
int bestValue = MAX_VALUE;
foreach (GameState child in gs.GetChildren())
{
int value = MiniMax(child, depth - 1, true);
if(value.CompareTo(bestValue) < 0)
{
gs.SetHeuristicValue(value);
bestValue = value;
}
}
return bestValue;
}
}
public void GenerateStates(GameState gs, int depth, Boolean maxPlayer)
{
if(depth == 0 || gs.GetState().Equals(GameState.State.terminal))
{
return;
}
gs.FindChildrenStates(maxPlayer);
foreach(GameState child in gs.GetChildren())
{
if (maxPlayer)
{
GenerateStates(child, depth - 1, false);
}
else
GenerateStates(child, depth - 1, true);
}
}
