象棋人工智能的实现

浅浅的花香味﹌ 2022-08-20 12:12 267阅读 0赞

### 为了实现人机对战功能，必须实现象棋的人工智能，将象棋的每个棋子都赋予一定的权重，每走一步都计算分值，选择得分最高的一步，这是象棋人工智能的基本思想。 ###

#ifndef AI_H
        #define AI_H
        #include "cocos2d.h"
        USING_NS_CC;
        class SceneGame;
    
        class Step : public CCObject
        {
        public:
            int _moveid;
            int _killid;
            int _xFrom;
            int _yFrom;
            int _xTo;
            int _yTo;
            static Step* create(int moveid, int killid, int xFrom, int yFrom, int xTo, int yTo)
            {
                Step* step = new Step;
                step->_killid = killid;
                step->_moveid = moveid;
                step->_xFrom = xFrom;
                step->_xTo = xTo;
                step->_yFrom = yFrom;
                step->_yTo = yTo;
                step->autorelease();
                return step;
            }
        };
        class AI
        {
        public:
            AI(SceneGame *game);
    
            SceneGame *_game;
            Step *GenOneMove(int level=2);
            int getScore();
    
            static int _score[7];
            CCArray *getAllPossibleMove();
            void getAllPossibleMove(int idx,CCArray *arr);
    
            int getMinValue(int level,int maxScore);
            int getMaxValue(int level,int minScore);
            Step *_step;
        };
    
        #endif // AI_H

### 得分表 ###

int AI::_score[7]=
    {
        1000,
        10,
        10,
        100,
        50,
        50,
        20
    };

### 创建一步 ###

Step *AI::GenOneMove(int level)
    {
    
        int maxScore=-10000;
        Step *ret;
        //find all possible access an calcute the hights score
        CCArray *possibleMOve=getAllPossibleMove();
        CCObject *obj;
        CCARRAY_FOREACH(possibleMOve,obj)
        {
            Step *step=(Step*)obj;
            _game->fakeMove(step);
            int score=getMinValue(level-1,maxScore);
            //int score=getScore();
            _game->unfakeMove(step);
            if(score>maxScore)
            {
                maxScore=score;
                ret=step;
            }
        }
    
        return ret;
    
    }

### 最大值最小值算法 ###

int AI::getMinValue(int level,int maxScore)
    {
        if(level ==0)
        {
            return getScore();
        }
        int minScore=10000;
        CCArray *possibleMOve=getAllPossibleMove();
        CCObject *obj;
        CCARRAY_FOREACH(possibleMOve,obj)
        {
            Step *step=(Step*)obj;
            _game->fakeMove(step);
            int score=getMaxValue(level-1,minScore);
             _game->unfakeMove(step);
            if(score<=maxScore)
            {
                minScore=score;
                return minScore;
            }
    
    
            if(score<minScore)
            {
                minScore=score;
    
            }
    
        }
    
        return minScore;
    }
    int AI::getMaxValue(int level,int minScore)
    {
        if(level ==0)
        {
            return getScore();
        }
        int maxScore=-10000;
        CCArray *possibleMOve=getAllPossibleMove();
        CCObject *obj;
        CCARRAY_FOREACH(possibleMOve,obj)
        {
            Step *step=(Step*)obj;
            _game->fakeMove(step);
            int score=getMinValue(level-1,maxScore);
             _game->unfakeMove(step);
            if(score>=minScore)
            {
                maxScore=score;
                break;
            }
    
            if(score>maxScore)
            {
                maxScore=score;
    
            }
    
        }
    
        return maxScore;
    }

### 值得注意的是，象棋预先考虑的步骤越多，象棋越智能，但是当象棋考虑到第4步的时候，ubuntu就崩溃了，可以采用智能减枝算法，有效减少计算量。注意，当使用智能减枝时，一定要将假动作回移，不然会引起递归混乱。 ###