public Minimax FindNextMove(int depth)
{
Minimax ret = null;
MiniMax(depth, int.MinValue + 1, int.MaxValue - 1, out ret);
return(ret);
}
//http://en.wikipedia.org/wiki/Alpha-beta_pruning
public int MiniMax(int depth, int alpha, int beta, out Minimax childWithMax)
{
childWithMax = null;
if (depth == 0 || IsTerminalNode())
{
//When it is turn for PlayO, we need to find the minimum score.
RecursiveScore = m_Score;
return(m_TurnForPlayerX ? m_Score : -m_Score);
}
foreach (Minimax cur in GetChildren())
{
Minimax dummy;
int score = -cur.MiniMax(depth - 1, -beta, -alpha, out dummy);
if (alpha < score)
{
alpha = score;
childWithMax = cur;
if (alpha >= beta)
{
break;
}
}
}
RecursiveScore = alpha;
return(alpha);
}
/// <summary>
/// Uses dynamic difficulty adjustment and the minimax algorithum to make take a move.
/// </summary>
public void DynamicTakeTurn()
{
m_Difficulty = 5;
r = new Random();
int loses = totalGames - wins;
if (loses > wins)
{
int differece = loses - wins;
m_Difficulty = 5 - differece;
if (m_Difficulty < 1)
{
m_Difficulty = 1;
}
}
else if (wins > loses)
{
int difference = wins - loses;
m_Difficulty = 5 + wins;
if (winStreak > 3)
{
m_Difficulty++;
}
if (m_Difficulty > 8)
{
m_Difficulty = 8;
}
}
else
{
if (winStreak > 3)
{
m_Difficulty = 6;
}
else
{
m_Difficulty = 5;
}
}
int ranChance = 8 - m_Difficulty;
ranChance = r.Next(ranChance);
if (ranChance < m_Difficulty)
{
m_M.UpdateBoard(this.m_Arr);
Minimax max = m_M.FindNextMove(m_Difficulty);
this.m_Arr = max.MG;
m_Turn = 'X';
}
else
{
Randomisation();
}
}
/// <summary>
/// Assigns the starting inital values for the game and calls the gameplay loop
/// </summary>
/// <param name="dynamic">true or false, dynamic or static</param>
/// <param name="difficulty">The static difficulty value if applicable else 99</param>
/// <param name="UI">Display UI? True/False</param>
public void StartGame(bool dynamic, int difficulty, bool UI)
{
m_End = false;
m_Turn = 'X';
m_Arr = new char[] { '1', '2', '3', '4', '5', '6', '7', '8', '9' };
m_B = new Board();
m_M = new Minimax((char[])m_Arr.Clone(), false);
m_Dynamic = dynamic;
if (difficulty != 99)
{
m_Difficulty = difficulty;
}
if (UI)
{
if (ted == null || !ted.IsAlive)
{
ted = new Thread(LoadUI);
ted.Start();
}
}
GameplayLoop();
}
