上回讲过：
python+pygame实现五子棋人机对战之一
python+pygame实现五子棋人机对战之二
界面已经有了，并且可以支持鼠标操作选择菜单和人机对战开始下棋了，那电脑是如何应手落子呢？以下内容是通用的类，全部放在utils.py中
四、
最常见的基本棋型大体有以下几种：连五，活四，冲四，活三，眠三，活二，眠二了，下面简要讲解一下：
4.1 连五：五颗同色棋子连在一起
4.2 活四：由4枚同色棋子形成的两端没有对方棋子的四枚棋子
4.3 冲四一（连四）：由4枚同色棋子形成的一端有对方棋子的四枚棋子
4.4 冲四二（跳四）：由4枚同色棋子形成的中间没有对方棋子的四枚棋子。
4.5 眠四：由4枚同色棋子形成的两端有对方棋子的4枚棋子。 不能成五的四连。
相对比活四来说，冲四的威胁性就小了很多，此时，防守方只要跟着防守在那个唯一的连五点上，冲四就没法形成连五。
4.6 活三一（连三）：由3枚同色棋子形成连三、跳三。 再走一着可以形成活四的三。 两端都是威胁的活三。简称“连三”。
4.7 活三二（跳三）：由3枚同色棋子形成的中间没有对方棋子的三枚棋子。中间夹有一个威胁的活三。简称“跳三”。
4.8 眠三：由3枚同色棋子形成的两端有对方棋子的3枚棋子。 即再走一着可以形成冲四的三。眠三的形状是很丰富的。眠三的棋型与活三的棋型相比，危险系数下降不少，因为眠三棋型即使不去防守，下一手它也只能形成冲四，而对于单纯的冲四棋型，我们是可以防守住的。
活三可以形成眠三，但也能够形成活四。眠三只能够形成冲四。
4.9 活二 ：由2枚同色棋子形成的连二（由2枚同色棋子连在一起形成的两头没有对方棋子的2枚棋子。）、跳二（由2枚同色棋子形成的中间没有对方棋子的2枚棋子。）、大跳二（中间有两个空白位置的跳二）。
4.10 眠二 ：由2枚同色棋子形成的两端有对方棋子的2枚棋子。是能够形成眠三的二。
对于棋盘上每一个交叉点，会有8个方向连成五子的可能性，那么我们就利用算法算出所有的可能性，并根据它成五的概率给它打分，这样，得分最高的就是最好的落子点。
如何去实现呢？首先我们在8个方向上将其抽象成坐标的加减，例如水平向右，那么x+1，y不变，向右上，则x+1，y+1 .按正下方开始，逆时针8个方向就形成下面的数据结构：
directions = [[0, 1], [1, 1], [1, 0], [1, -1], [0, -1], [-1, -1], [-1, 0], [-1, 1]]获取当前坐标的各个方向上棋子属性，返回1代表白棋，返回2代表黑棋，返回0代表没有棋，返回5表示在棋盘外。
from params import Params
rows = int(Params.get('ROWS'))
blocksize = int(Params.get('blockSize'))
width = int(Params.get('WIDTH'))
height = int(Params.get('HEIGHT'))
# 获取当前坐标的各个方向上棋子属性，返回1代表白棋，返回2代表黑棋，返回0代表没有棋，返回5表示在棋盘外
def getpointpiece(_mapchess,pos, src, offset):
# 8个方向
directions = [[0, 1], [1, 1], [1, 0], [1, -1], [0, -1], [-1, -1], [-1, 0], [-1, 1]]
x1, y1 = pos
x1 = x1 + directions[src - 1][0] * offset * blocksize
y1 = y1 + directions[src - 1][1] * offset * blocksize
if x1 > 588 or y1 > 588 or x1 < 28 or y1 < 28:
return 5
else:
return _mapchess[str(x1) + ',' + str(y1)]再加上刚才分析的五子棋的基本棋型，可以设计出一个打分算法：
from params import Params
rows = int(Params.get('ROWS'))
blocksize = int(Params.get('blockSize'))
width = int(Params.get('WIDTH'))
height = int(Params.get('HEIGHT'))
# 判断每个点的value，用来排序该点下棋的可行性
def pointvalue(_mapchess, pos, flag1, flag2):
value = 0 #加权值
for i in range(1, 9): #8个方向
# 11111 连五
if getpointpiece(_mapchess,pos, i, 1) == flag1 and \
getpointpiece(_mapchess,pos, i, 2) == flag1 and \
getpointpiece(_mapchess,pos, i, 3) == flag1 and \
getpointpiece(_mapchess,pos, i, 4) == flag1 and \
getpointpiece(_mapchess,pos, i, 5) == flag1:
value += 1000000
# *1111_ 活四
if getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == flag1 and \
getpointpiece(_mapchess, pos, i, 3) == flag1 and \
getpointpiece(_mapchess, pos, i, 4) == flag1 and \
getpointpiece(_mapchess, pos, i, 5) == 0:
value += 50000
# *11112 冲四1，冲四指加一个点就是连五，比活四威力小得多
if getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == flag1 and \
getpointpiece(_mapchess, pos, i, 3) == flag1 and \
getpointpiece(_mapchess, pos, i, 4) == flag1 and \
getpointpiece(_mapchess, pos, i, 5) == flag2:
value += 30000
# 1*111 冲四2
if getpointpiece(_mapchess, pos, i, -1) == flag1 and \
getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == flag1 and \
getpointpiece(_mapchess, pos, i, 3) == flag1:
value += 30000
# 11*11 冲四3
if getpointpiece(_mapchess, pos, i, -2) == flag1 and \
getpointpiece(_mapchess, pos, i, -1) == flag1 and \
getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == flag1:
value += 30000
# *111_ 活三1，活三可以形成活四的三
if getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == flag1 and \
getpointpiece(_mapchess, pos, i, 3) == flag1 and \
getpointpiece(_mapchess, pos, i, 4) == 0:
value += 20000
# *1_11_ 活三2
if getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == 0 and \
getpointpiece(_mapchess, pos, i, 3) == flag1 and \
getpointpiece(_mapchess, pos, i, 4) == flag1 and \
getpointpiece(_mapchess, pos, i, 5) == 0:
value += 20000
# *1112 眠三1 眠三是只能形成冲四的三
if getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == flag1 and \
getpointpiece(_mapchess, pos, i, 3) == flag1 and \
getpointpiece(_mapchess, pos, i, 4) == flag2:
value += 15000
# _1_112 眠三2
if getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == 0 and \
getpointpiece(_mapchess, pos, i, 3) == flag1 and \
getpointpiece(_mapchess, pos, i, 4) == flag1 and \
getpointpiece(_mapchess, pos, i, 5) == flag2:
value += 15000
# _11_12 眠三3
if getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == flag1 and \
getpointpiece(_mapchess, pos, i, 3) == 0 and \
getpointpiece(_mapchess, pos, i, 4) == flag1 and \
getpointpiece(_mapchess, pos, i, 5) == flag2:
value += 15000
# 1__11 眠三4
if getpointpiece(_mapchess, pos, i, -1) == flag1 and \
getpointpiece(_mapchess, pos, i, 1) == 0 and \
getpointpiece(_mapchess, pos, i, 2) == flag1 and \
getpointpiece(_mapchess, pos, i, 3) == flag1:
value += 15000
# 1_1_1 眠三5
if getpointpiece(_mapchess, pos, i, -1) == flag1 and \
getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == 0 and \
getpointpiece(_mapchess, pos, i, 3) == flag1:
value += 15000
# 2_111_2 眠三6
if getpointpiece(_mapchess, pos, i, -1) == flag2 and \
getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == flag1 and \
getpointpiece(_mapchess, pos, i, 3) == flag1 and \
getpointpiece(_mapchess, pos, i, 4) == 0 and \
getpointpiece(_mapchess, pos, i, 5) == flag2:
value += 15000
# __11__ 活二1 活二能够形成活三的二
if getpointpiece(_mapchess, pos, i, -1) == 0 and \
getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == flag1 and \
getpointpiece(_mapchess, pos, i, 3) == 0 and \
getpointpiece(_mapchess, pos, i, 4) == 0:
value += 10000
# _1_1_ 活二2
if getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == 0 and \
getpointpiece(_mapchess, pos, i, 3) == flag1 and \
getpointpiece(_mapchess, pos, i, 4) == 0:
value += 10000
# 211__ 眠二1 ，能够形成眠三的二
if getpointpiece(_mapchess, pos, i, -1) == flag2 and \
getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == flag1 and \
getpointpiece(_mapchess, pos, i, 3) == 0 and \
getpointpiece(_mapchess, pos, i, 4) == 0 and \
getpointpiece(_mapchess, pos, i, 5) == 0:
value += 1000
#21_1__ 眠二2
if getpointpiece(_mapchess, pos, i, -1) == flag2 and \
getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == 0 and \
getpointpiece(_mapchess, pos, i, 3) == flag1 and \
getpointpiece(_mapchess, pos, i, 4) == 0 and \
getpointpiece(_mapchess, pos, i, 5) == 0:
value += 1000
#21__1_ 眠二3
if getpointpiece(_mapchess, pos, i, -1) == flag2 and \
getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == 0 and \
getpointpiece(_mapchess, pos, i, 3) == 0 and \
getpointpiece(_mapchess, pos, i, 4) == flag1 and \
getpointpiece(_mapchess, pos, i, 5) == 0:
value += 1000
#*1___1 眠二4
if getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == 0 and \
getpointpiece(_mapchess, pos, i, 3) == 0 and \
getpointpiece(_mapchess, pos, i, 4) == 0 and \
getpointpiece(_mapchess, pos, i, 5) == flag1:
value += 1000
# *1__
if getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == 0 and \
getpointpiece(_mapchess, pos, i, 3) == 0:
value += 30
# *1_
if getpointpiece(_mapchess, pos, i, 1) == flag1 and \
getpointpiece(_mapchess, pos, i, 2) == 0:
value += 20
# *1
if getpointpiece(_mapchess, pos, i, 1) == flag1:
value += 10
return value
# 获取当前坐标的各个方向上棋子属性，返回1代表白棋，返回2代表黑棋，返回0代表没有棋，返回5表示在棋盘外
def getpointpiece(_mapchess,pos, src, offset):
# 8个方向
directions = [[0, 1], [1, 1], [1, 0], [1, -1], [0, -1], [-1, -1], [-1, 0], [-1, 1]]
x1, y1 = pos
x1 = x1 + directions[src - 1][0] * offset * blocksize
y1 = y1 + directions[src - 1][1] * offset * blocksize
if x1 > 588 or y1 > 588 or x1 < 28 or y1 < 28:
return 5
else:
return _mapchess[str(x1) + ',' + str(y1)]这样就可以实现：当人下了棋后，电脑通过这个算法找出最有利的落子点，然后就在那里下棋。
注：本程序只是提供一个思路而已，并不是最优解。代码中value值可以自行修改，算法可以自己再设计，例如可以假如双活三之类的必须防御的应手。
如何判断胜负呢？待续。。。
python+pygame实现五子棋人机对战之四
