Hi, I’m implementing the minimax algorythm to my Panda3d Tic-Tac-Toe game, and have a problem.

I have exacly the same method for a game in system console and it works great.

The problem is that my win checking functions are not returning True when filling the board with marks for computer playing with himself. I don’t know what is causing it, maybe the loop is working differently in MyApp class??? i don’t really know.

I’m new to programming so don’t know really what can cause it.

“BoardSize” is the variable defining the size of the board (3 or 4). So when is set to 3, It doesn’t check

the entire 4x4 board.

BoardList is the board made of four lists. It is outside the MyApp class but It doesn’t really matter.

```
Board0=['','','','']
Board1=['','','','']
Board2=['','','','']
Board3=['','','','']
BoardList=[Board0,Board1,Board2,Board3]
```

Here is the computer move and minimax function code:

(I’m sorry for naming functions with a big letter, I’ll fix that later

```
def computer(self, max_depth):
self.max_score=-1000
self.best_moveR = 0
self.best_moveC = 0
self.random_moveR = random.randint(0, self.BoardSize-1)
self.random_moveC = self.random_moveR
for n in range(0,self.BoardSize):
for i in range(0,self.BoardSize):
if BoardList[n][i]=='':
BoardList[n].pop(i)
BoardList[n].insert(i,'o')
self.score = self.minimax(0,False,max_depth)
BoardList[n].pop(i)
BoardList[n].insert(i,'')
if (self.score > self.max_score):
self.max_score = self.score
self.best_moveR = n
self.best_moveC= i
print(self.best_moveR)
print(self.best_moveC)
self.insertLetter('o', self.best_moveR,self.best_moveC)
return self.best_moveR,self.best_moveC
def minimax(self, depth, isMaximizing,max_depth):
if (self.HorizontalWinC('o') or self.PlayerWinsVC('o') or self.PlayerWinsD1C('o') or self.PlayerWinsD2C('o')):
return 1
if (self.HorizontalWinC('x') or self.PlayerWinsVC('x') or self.PlayerWinsD1C('x') or self.PlayerWinsD2C('x')):
return -1
if (self.DrawC('o') or self.DrawC('x') or depth==max_depth):
return 0
if isMaximizing:
self.max_score = -1000
for n in range(0,self.BoardSize):
for i in range(0,self.BoardSize):
if BoardList[n][i]=='':
BoardList[n].pop(i)
BoardList[n].insert(i,'o')
self.score = self.minimax(depth+1,False,max_depth)
BoardList[n].pop(i)
BoardList[n].insert(i,'')
if (self.score > self.max_score):
self.max_score = self.score
return self.max_score
else:
self.max_score = 800
for n in range(0,self.BoardSize):
for i in range(0,self.BoardSize):
if BoardList[n][i]=='':
BoardList[n].pop(i)
BoardList[n].insert(i,'x')
self.score = self.minimax(depth+1,True,max_depth)
BoardList[n].pop(i)
BoardList[n].insert(i,'')
if (self.score < self.max_score):
self.max_score = self.score
return self.max_score
```

Here are the win check functions:

```
def HorizontalWinC(self,mark):
for i in range(0,self.BoardSize):
print(BoardList[i].count(mark))
#checking horizontal win
if BoardList[i].count(mark)==self.BoardSize:
return True
#vertical win
def PlayerWinsVC(self,mark):
for i in range(0,self.BoardSize):
self.VC[mark][i]=0
for i in range(0,self.BoardSize):
#counting marks x or o in vertical lines
for n in range(0,self.BoardSize):
if BoardList[n][i]==mark:
self.VC[mark][i]+=1
print('VC'+str(self.VC))
for i in range(0,self.BoardSize):
if self.VC[mark][i]==self.BoardSize:
return True
#diagonal win 1
def PlayerWinsD1C(self,mark):
self.D1C[mark]=0
for i in range(0,self.BoardSize):
if BoardList[i][i]==mark:
self.D1C[mark]+=1
print('D1C'+str(self.D1C))
if self.D1C[mark]==self.BoardSize:
return True
#diagonal win 2
def PlayerWinsD2C(self,mark):
self.D2C[mark]=0
for i in range(0,self.BoardSize):
if BoardList[self.BoardSize-1-i][i]==mark:
self.D2C[mark]+=1
print('D2C'+str(self.D2C))
if self.D2C[mark]==self.BoardSize:
return True
def DrawC(self,mark):
self.D1DrawC[mark]=False
self.D2DrawC[mark]=False
for i in range(0,self.BoardSize):
self.VC[mark][i]=0
#diagonal draw 1
for i in range(0,self.BoardSize):
if BoardList[i][i]==mark:
self.D1DrawC[mark]=True
print('D1DrawC',self.D1DrawC)
#diagonal draw 2
for i in range(0,self.BoardSize):
if BoardList[self.BoardSize-1-i][i]==mark:
self.D2DrawC[mark]=True
print('D2DrawC',self.D2DrawC)
self.VDrawCountC=0
self.HDrawCountC=0
#vertical draw
for i in range(0,self.BoardSize):
if self.VC['x'][i]>=1 and self.VC['o'][i]>=1:
self.VDrawCountC+=1
print('VDrawCountC',self.VDrawCountC)
#horizonal draw
for i in range(0,self.BoardSize):
if BoardList[i].count('x')>=1 and BoardList[i].count('o')>=1:
self.HDrawCountC+=1
print('HDrawCountC',self.HDrawCountC)
#draw conditions
if (self.D1DrawC['x']==True and self.D1DrawC['o']==True
and self.D2DrawC['x']==True and self.D2DrawC['o']==True
and self.VDrawCountC==self.BoardSize
and self.HDrawCountC==self.BoardSize):
return True
```