www.pudn.com > 1223456.rar > IDAlphabetaEngine.cpp

// IDAlphabeta.cpp: implementation of the CIDAlphabetaEngine class. 
// 
////////////////////////////////////////////////////////////////////// 
 
#include "stdafx.h" 
#include "IDAlphabetaEngine.h" 
 
////////////////////////////////////////////////////////////////////// 
// Construction/Destruction 
////////////////////////////////////////////////////////////////////// 
 
CIDAlphabetaEngine::CIDAlphabetaEngine() 
{ 
 
} 
 
CIDAlphabetaEngine::~CIDAlphabetaEngine() 
{ 
 
} 
 
CIDAlphabetaEngine::SearchAGoodMove(BYTE position[][9]) 
{ 
	CHESSMOVE backupmove;//最佳走法的备份 
 
	memcpy(CurPosition,position,90); 
	m_nTimeCount=GetTickCount(); 
 
	//迭代深化搜索 
	for(m_nMaxDepth=1;m_nMaxDepth<=m_nSearchDepth;m_nMaxDepth++) 
		if(AlphaBeta(m_nMaxDepth,-20000,20000)!=66666)//如果本次搜索没有被中止，保存最佳走法 
			backupmove=m_cmBestMove; 
 
	m_umUndoMove.cmChessMove=m_cmBestMove; 
	m_umUndoMove.nChessID=MakeMove(&m_cmBestMove); 
	 
	memcpy(position,CurPosition,90);//传出最佳走法 
} 
 
int CIDAlphabetaEngine::AlphaBeta(int nDepth, int alpha, int beta) 
{ 
	int score; 
	int Count,i; 
	BYTE type; 
 
	i=IsGameOver(CurPosition, nDepth); 
	if(i!=0) 
		return i; 
 
	if(nDepth<=0)//叶子节点取估值 
		return m_pEval->Eveluate(CurPosition,(m_nMaxDepth-nDepth)%2,m_nUserChessColor); 
	 
	Count=m_pMG->CreatePossibleMove(CurPosition,nDepth,(m_nMaxDepth-nDepth)%2,m_nUserChessColor); 
	if(nDepth==m_nMaxDepth) 
	{ 
		//在根节点设定进度条 
		m_pThinkProgress->SetRange(0,Count); 
		m_pThinkProgress->SetStep(1); 
	} 
 
	//此下 if语句之内代码，用于调整底层节点排列顺序 
	//如果某走法在上次迭代中是 BestMove，将其排在第一位 
	if(nDepth==m_nMaxDepth && m_nMaxDepth>1) 
		for(i=1;im_MoveList[nDepth][i].From.x==m_cmBestMove.From.x 
				&& m_pMG->m_MoveList[nDepth][i].From.y==m_cmBestMove.From.y 
				&& m_pMG->m_MoveList[nDepth][i].To.x==m_cmBestMove.To.x	 
				&& m_pMG->m_MoveList[nDepth][i].To.y==m_cmBestMove.To.y)	 
			{ 
				//交换两个走法的位置 
				m_pMG->m_MoveList[nDepth][i]=m_pMG->m_MoveList[nDepth][0]; 
				m_pMG->m_MoveList[nDepth][0]=m_cmBestMove; 
			}				 
		}	 
 
	for(i=0;iStepIt();//走进度条 
			if(GetTickCount()-m_nTimeCount>=1000000) 
				return 66666;//返回中止标记 
		} 
 
		type=MakeMove(&m_pMG->m_MoveList[nDepth][i]);  //产生子节点 
		score=-AlphaBeta(nDepth-1,-beta,-alpha);		  //递归搜索 
		UnMakeMove(&m_pMG->m_MoveList[nDepth][i],type);//撤销子节点 
 
		if(score>alpha) 
		{ 
			alpha=score; 
			if(nDepth==m_nMaxDepth) 
				m_cmBestMove=m_pMG->m_MoveList[nDepth][i];//保存最佳走法 
		} 
        if(alpha>=beta)  
              break;//beta剪枝			 
	} 
 
	return alpha;//返回最大值 
}