较高人工智能的人机博弈程序实现(多个算法结合)含C++源码

较高人工智能的人机博弈程序实现(多个算法结合)含C++源码

 本文由恋花蝶最初发表于http://blog.csdn.net/lanphaday 上，您可以转载、引用、打印和分发等，但必须保留本文完整和包含本声明，否则必究责任。

 到昨天晚上，Topcoder Marathon Match 6结束了，我取得了第18名的成绩，已经是自己参加Marathon四次以来的最好名次啦，高兴ing。因为这次的题目比较偏：写一个人工智能程序和服务器端的程序进行博弈。人机博弈是一门比较专的学科，大部分中国高手都不能快速的在比赛中学习和实现一些复杂的算法，以致成绩不太如意；我挟之前对这方面的了解，做得还算行，所以把代码公开出来，可以多一点中文方面的资料和源码给大家参考，我也感到非常荣幸。

 比赛的题目请看这里：http://www.topcoder.com/longcontest/?module=ViewProblemStatement&rd=10118&pm=6759  主要的游戏规则也是在这里的，我就不在这里重复啦，主要讲讲我的代码用到了什么算法。麻将虽小，五脏俱全，主要应用的算法有主要变量搜索(PVS)、历史启发(HH)、杀手启发(KH)、Null
Move和迭代深化(ID)，可惜后来不够时间实现置换表(TT)，不然可以多一个算法了。代码里还实现了时间控制策略，可以几乎用尽20秒的测试时间，为争取更好的着法提供了保证。还有值得一提的是棋盘表示，我使用了棋盘表、棋子位置表结合的方式来表示，后来发现加上空位表的话，可以加快不少走法生成和估值的速度。反正棋盘表示是一切的基础，一种好的表示方法可以带来很大的性能提升。对于代码，大家注意class SE里的search_move和pvs两个函数，上述的算法和策略都在那里。class MG是关于棋盘表示、走法生成和估值的，class
KH和class HH分别是杀手启发和历史启发。Null Move是简单有效的算法，不过我的实现里是比较简单的那种，如果有兴趣，可以查询其它资料。

 

 讲了这么多，应该说一下这份代码的计算能力：以6*6的棋盘为例，这份代码在VC6的release模式下编译运行可以在1秒内搜索并评估83万个叶子节点，计算层次在8-9层；如果用MiniMax算法不进行剪枝，只能搜索到3-4层（测试机器皆为超线程P4 3.0G＋1G内存）。这就是算法的力量吧。另声明一下，本代码未作优化，不代表我不懂，只是没有时间，看的朋友请海涵了。 

下面是代码，在VC和G++上皆可编译、执行

因为比赛期间写的，代码比较乱，但整体的风格还是可以的，复制到IDE上看可能会更好看些。

代码如下：

#include < iostream >
#include < cstdlib >
#include < ctime >
#include < cassert >
#include < vector >
#include < algorithm >

using namespace std;

typedef unsigned int UINT;
typedef UINT MOVE;

const int INFINITY = 100000000 ;
const int MAX_DEPTH = 16 ;

const UINT max_board_size = 256 ;
const UINT max_stones_cnt = 256 ;

const UINT empty = 0 ;
const UINT my_color = 1 ;
const UINT svr_color = 2 ;

#ifdef WIN32
const clock_t all_time = 19200 ;
#else
const clock_t all_time = 19200000 ;
#endif

const UINT check_time_cnt = 0x00001fff ;

#define is_empty(x) (x==empty)

#define opp_color(x) (x==my_color?svr_color:my_color)

int leaf_cnt = 0 ;

class MG
{
private :
UINT N_;
UINT board_[max_board_size];
UINT stones_[max_stones_cnt];
private :
void extend(UINT pos, unsigned char * eht, unsigned char * est, UINT & area, UINT & round);

public :
MOVE move_table[MAX_DEPTH][max_board_size];
UINT curr_stones_cnt;
UINT curr_board_size;
void set_N( int n) {
N_ = n;
curr_board_size = n * n;
curr_stones_cnt = 0 ;
memset(board_, 0 , sizeof (UINT) * max_board_size);
memset(stones_, 0 , sizeof (UINT) * max_stones_cnt);
}
void make_move( int idx, int color) {
board_[idx] = color;
stones_[curr_stones_cnt ++ ] = idx;
}
void unmake_move( int idx) {
board_[idx] = empty;
-- curr_stones_cnt;
}
inline bool is_game_over() { return curr_stones_cnt == curr_board_size;}
UINT gen_move( int depth);
int evaluatoin( int color);
int evaluatoin_4_end( int color);
void print_board()
{
int cnt = 0 ;
for (UINT i = 0 ; i < curr_board_size; ++ i)
{
if (is_empty(board_[i]))
cout << " o " ;
else
cout << ((board_[i] == my_color) ? " @ " : " - " );
++ cnt;
if (cnt == N_)
{
cnt = 0 ;
cout << endl;
}
}
}
bool can_move(MOVE move) { return is_empty(board_[move]);}
void remove_killers( int depth, int move_cnt, MOVE * killers, int killers_cnt)
{
for ( int i = 0 ; i < killers_cnt; ++ i)
{
MOVE m = killers[i];
for ( int j = 0 ; j < move_cnt; ++ j)
{
if (move_table[depth][j] != m)
continue ;
for ( int k = j + 1 ; k < move_cnt; ++ k)
{
move_table[depth][k - 1 ] = move_table[depth][k];
}
break ;
}
}
}
} ;

UINT MG::gen_move( int depth)
{
int cnt = 0 ;
for (UINT i = 0 ; i < curr_board_size; ++ i)
{
if (is_empty(board_[i]))
move_table[depth][cnt ++ ] = i;
}
return cnt;
}

int MG::evaluatoin( int color)
{
if (curr_stones_cnt + 1 == curr_board_size)
{
for ( int i = 0 ; i < curr_board_size; ++ i)
{
if (is_empty(board_[i]))
{
board_[i] = color;
int value = - evaluatoin_4_end(opp_color(color));
board_[i] = empty;
return value;
}
}
}
++ leaf_cnt;
unsigned char extended_hash_table[max_board_size] = { 0 } ;

int my_score = 0 , svr_score = 0 ;
for (UINT i = 0 ; i < curr_stones_cnt; ++ i)
{
UINT pos = stones_[i];
if (extended_hash_table[pos])
continue ;
UINT area = 0 , round = 0 ;
unsigned char extended_space_table[max_board_size] = { 0 } ;
extend(pos, extended_hash_table, extended_space_table, area, round);
if (board_[pos] == my_color)
{
my_score += area * area * round;
}
else
{
svr_score += area * area * round;
}
}
if (color == my_color)
return my_score - svr_score;
return svr_score - my_score;
}

int MG::evaluatoin_4_end( int color)
{
++ leaf_cnt;
unsigned char extended_hash_table[max_board_size] = { 0 } ;

int my_score = 0 , svr_score = 0 ;
for (UINT i = 0 ; i < curr_stones_cnt; ++ i)
{
UINT pos = stones_[i];
if (extended_hash_table[pos])
continue ;
UINT area = 0 , round = 0 ;
unsigned char extended_space_table[max_board_size] = { 0 } ;
extend(pos, extended_hash_table, extended_space_table, area, round);
if (board_[pos] == my_color)
{
my_score += area * area;
}
else
{
svr_score += area * area;
}
}
if (color == my_color)
return my_score - svr_score;
return svr_score - my_score;
}

void MG::extend(UINT pos, unsigned char * eht, unsigned char * est, UINT & area, UINT & round)
{
const UINT round_cnt = 4 ;
int is [round_cnt] = { - N_, - 1 , 1 , N_} ;

++ area;
eht[pos] = 1 ;

for (UINT i = 0 ; i < round_cnt; ++ i)
{
int new_idx = pos + is [i];
if (new_idx < 0 || new_idx >= curr_board_size)
continue ;
if (i == 1 && pos % N_ == 0 )
continue ;
if (i == 2 && new_idx % N_ == 0 )
continue ;
if (is_empty(board_[new_idx]) && ( ! est[new_idx]))
{
++ round;
est[new_idx] = 1 ;
continue ;
}
if (eht[new_idx])
continue ;
if (board_[new_idx] == board_[pos])
extend(new_idx, eht, est, area, round);
}
}

class HH
{
private :
UINT board_[ 2 ][max_board_size];
public :
void reset() {memset(board_, 0 , sizeof (UINT) * max_board_size);}
void update_value( int depth, int color, MOVE move);
MOVE get_best(MOVE * move_list, int color, int cnt);
} ;

void HH::update_value( int depth, int color, MOVE move)
{
board_[color - 1 ][move] += ( 1 << depth);
}

MOVE HH::get_best(MOVE * move_list, int color, int cnt)
{
int real_color = color - 1 ;
MOVE * p = move_list;
int best = board_[real_color][ * move_list];
int best_idx = 0 ;
for ( int i = 1 ; i < cnt; ++ i)
{
++ move_list;
if (board_[real_color][ * move_list] <= best)
continue ;
best = board_[real_color][ * move_list];
best_idx = i;
}
MOVE tmp = * p;
* p = p[best_idx];
p[best_idx] = tmp;
return * p;
}

struct KH_item
{
MOVE move;
int cnt;
} ;

class less_than
{
public :
inline bool operator ()( const KH_item & lhs, const KH_item & rhs)
{
return lhs.cnt < rhs.cnt;
}
} ;

const int max_kh_item_cnt = 4 ;

class KH
{
private :
KH_item KH_table[MAX_DEPTH][max_kh_item_cnt];
int cnt_table[MAX_DEPTH];
public :
void add_to_kh(MOVE move, int depth)
{
int cnt_mini_idx = 0 ;
int cnt_mini = KH_table[depth][ 0 ].cnt;
int i = 0 ;
for (i = 0 ; i < cnt_table[depth]; ++ i)
{
KH_item & tmp = KH_table[depth][i];
if (tmp.move == move)
{
++ tmp.cnt;
return ;
}
if (tmp.cnt < cnt_mini)
{
cnt_mini_idx = i;
cnt_mini = tmp.cnt;
}
}
if (i < max_kh_item_cnt)
{
KH_table[depth][i].move = move;
++ (cnt_table[depth]);
}
else
{
KH_item & tmp = KH_table[depth][cnt_mini_idx];
tmp.move = move;
tmp.cnt = 1 ;
}
}
int get_killers(MOVE * killers, int depth)
{
sort < KH_item *> (KH_table[depth], KH_table[depth] + cnt_table[depth], less_than());
int i = 0 ;
for (i = 0 ; i < cnt_table[depth]; ++ i)
{
killers[i] = KH_table[depth][i].move;
}
return i;
}
void reset()
{
memset(cnt_table, 0 , sizeof ( int ) * MAX_DEPTH);
memset(KH_table, 0 , sizeof (KH_item) * MAX_DEPTH * max_kh_item_cnt);
}
} ;

class SE
{
private :
MG mg;
HH hh;
KH kh;
int N_;
int best_move;
int max_depth_;
public :
void print_board()
{
mg.print_board();
}
void set_N( int N)
{
N_ = N;
used_time = 0 ;
best_move = 0xffff ;
mg.set_N(N);
}
vector < int > get_best_move()
{
int row = best_move / N_;
int col = best_move % N_;
vector < int > move;
move.push_back(row);
move.push_back(col);
return move;
}
void do_move( int row, int col, int color)
{
mg.make_move(row * N_ + col, color);
}
void make_sure_best_move_first(MOVE * moves, int cnt, MOVE best_move);
vector < int > search_move( int max_depth);
int pvs( int , int , int , int , int );
private :
clock_t bgn_time;
clock_t used_time;
clock_t curr_time_limit;
} ;

void SE::make_sure_best_move_first(MOVE * moves, int cnt, MOVE best_move)
{
for ( int i = 0 ; i < cnt; ++ i)
{
if (moves[i] == best_move)
{
moves[i] = moves[ 0 ];
moves[ 0 ] = best_move;
}
}
}

vector < int > SE::search_move( int max_depth)
{
leaf_cnt = 1 ;
bgn_time = clock(); // ³õʼʱ¼ä
// ¼ÆËã±¾´ÎʱÏÞ
UINT leave_space_cnt = mg.curr_board_size - mg.curr_stones_cnt;
if (leave_space_cnt >= 2 )
leave_space_cnt /= 2 ;
curr_time_limit = (all_time - used_time) / leave_space_cnt;
if (curr_time_limit > all_time || curr_time_limit < 0 )
{
curr_time_limit = 1 ;
}

if (leave_space_cnt < mg.curr_board_size / 3 )
curr_time_limit = (( double )curr_time_limit) * ( 1.4 );
else if (leave_space_cnt < mg.curr_board_size / 2 )
curr_time_limit = (( double )curr_time_limit) * ( 1.3 );

if (N_ > 12 )
curr_time_limit = (( double )curr_time_limit) * ( 0.9 );

hh.reset();
kh.reset();
int md = 0 ;
int backup_max_depth = max_depth;
while (md < max_depth)
{
++ md;
max_depth_ = md;
pvs(md, my_color, 0 , - INFINITY, INFINITY);

if (max_depth >= backup_max_depth)
{
// »¹ÓÐʱ¼ä£¿
if (clock() - bgn_time < curr_time_limit)
{
// ²»»á¶ÑÕ»Òç³ö£¿ÔÙËã¶àÒ»²ã
if (max_depth < MAX_DEPTH - 1 )
++ max_depth;
}
}
if (clock() - bgn_time >= curr_time_limit)
{
break ;
}
}
clock_t curr_used = clock() - bgn_time;
used_time += curr_used; // Ôö¼ÓÓõôµÄʱ¼ä
return get_best_move();
}

int SE::pvs( int depth, int color, int nullmove, int alpha, int beta)
{
if (mg.is_game_over())
return mg.evaluatoin_4_end(color);
if (depth <= 0 )
return mg.evaluatoin(color);
if ((leaf_cnt & check_time_cnt) == 0 ) // ¼ì²âÊÇ·ñ³¬Ê±
{
if (clock() - bgn_time >= curr_time_limit)
return mg.evaluatoin(color);
}

// Null Move
if (depth < max_depth_ && nullmove == 0 )
{
int value = - pvs(depth - 2 , opp_color(color), 1 , - alpha - 1 , - alpha);
if (value >= beta)
{
return value;
}
}

// killer move
int best;
MOVE bm = 0xffff ;
MOVE killers[max_kh_item_cnt];
int killers_cnt = kh.get_killers(killers, depth);

if (killers_cnt > 0 && depth == max_depth_)
make_sure_best_move_first(killers, killers_cnt, best_move);

for ( int k = 0 ; k < killers_cnt; ++ k)
{
MOVE m = killers[k];
if ( ! mg.can_move(m))
continue ;
mg.make_move(m, color);
best = - pvs(depth - 1 , opp_color(color), 0 , - alpha - 1 , - alpha);
if (best >= beta)
{
if (depth == max_depth_)
best_move = m;
kh.add_to_kh(m, depth);
hh.update_value(depth, color, m);
mg.unmake_move(m);
return best;
}
else if (best > alpha)
{
alpha = best;
bm = m;
}
mg.unmake_move(m);
if ((leaf_cnt & check_time_cnt) == 0 ) // ¼ì²âÊÇ·ñ³¬Ê±
{
if (clock() - bgn_time >= curr_time_limit)
break ;
}
}

// PVS
int move_cnt = mg.gen_move(depth);

if (depth == max_depth_)
make_sure_best_move_first(mg.move_table[depth], move_cnt, best_move);

if (killers_cnt == 0 || bm == 0xffff ) // bm == 0xffff±íʾkillersÎÞЧ£¡
{
if (depth == max_depth_)
bm = mg.move_table[depth][ 0 ];
else
bm = hh.get_best(mg.move_table[depth], color, move_cnt);
mg.make_move(bm, color);
best = - pvs(depth - 1 , opp_color(color), 0 , - beta, - alpha);
mg.unmake_move(bm);
}
else
{
// remove killers from move_table
if (killers_cnt > 0 )
mg.remove_killers(depth, move_cnt, killers, killers_cnt);
MOVE bm_;
if (depth == max_depth_)
bm_ = mg.move_table[depth][ 0 ];
else
bm_ = hh.get_best(mg.move_table[depth], color, move_cnt);
mg.make_move(bm_, color);
int best_ = - pvs(depth - 1 , opp_color(color), 0 , - beta, - alpha);
if (best_ > best)
{
best = best_;
bm = bm_;
}
mg.unmake_move(bm_);
}
for ( int i = 1 ; i < move_cnt; ++ i)
{
if (best >= beta)
break ;
if (best > alpha)
alpha = best;

if ((leaf_cnt & check_time_cnt) == 0 ) // ¼ì²âÊÇ·ñ³¬Ê±
{
if (clock() - bgn_time >= curr_time_limit)
break ;
}

MOVE m = hh.get_best(mg.move_table[depth] + i, color, move_cnt - i);
mg.make_move(m, color);
int value = - pvs(depth - 1 , opp_color(color), 0 , - alpha - 1 , - alpha);
if (value > alpha && value < beta)
{
best = - pvs(depth - 1 , opp_color(color), 0 , - beta, - value);
bm = m;
}
else if (value > best)
{
best = value;
bm = m;
}
mg.unmake_move(m);
}
if (depth == max_depth_)
best_move = bm;
if (best >= alpha)
{
kh.add_to_kh(bm, depth);
hh.update_value(depth, color, bm);
}
return best;
}

class PseudoTonga
{
public :
vector < int > move( int row, int col);
vector < int > init( int N, int row, int col);
private :
int N_;
SE se;
void do_move( int row, int col, int color);
} ;

vector < int > PseudoTonga::init( int N, int row, int col)
{
N_ = N;
se.set_N(N);

int r = 0 , c = 0 ;

if (row >= 0 || col >= 0 )
{
return move(row, col);
}

vector < int > move;
r = c = N / 2 ;
do_move(r, c, my_color);
move.push_back(r);
move.push_back(c);
cout << " player: row = " << move[ 0 ] << " , col = " << move[ 1 ] << " ; " ;
return move;
}

vector < int > PseudoTonga::move( int row, int col)
{
do_move(row, col, svr_color);
cout << " server: row = " << row << " , col = " << col << " ; " ;
vector < int > move;
int d = 3 ;
move = se.search_move(d);
do_move(move[ 0 ], move[ 1 ], my_color);
cout << " player: row = " << move[ 0 ] << " , col = " << move[ 1 ] << " ; " ;
cout << " leaf count is " << leaf_cnt << endl;
return move;
}

void PseudoTonga::do_move( int row, int col, int color)
{
se.do_move(row, col, color);
}

int main()
{
PseudoTonga pt;
pt.init(6, 2, 2);
pt.move(2,4);
return 0;
}