initial commitHEADmaster

1 files changed, 131 insertions, 0 deletions

diff --git a/tictactoe.py b/tictactoe.py
new file mode 100644
index 0000000..f6b2c70
--- /dev/null
+++ b/tictactoe.py
@@ -0,0 +1,131 @@
+import random
+
+board = ['1', '2', '3', '4', '5', '6', '7', '8', '9']
+wincombs = ((0, 1, 2), (3, 4, 5), (6, 7, 8), (0, 3, 6), (1, 4, 7), (2, 5, 8), (0, 4, 8), (2, 4, 6))
+player1 = 'x'
+player2 = 'o'
+
+def render(board):
+    print(f'''
+ {board[0]} │ {board[1]} │ {board[2]} 
+───┼───┼───
+ {board[3]} │ {board[4]} │ {board[5]} 
+───┼───┼───
+ {board[6]} │ {board[7]} │ {board[8]}''')
+
+def evaluate(board):
+    for wincomb in wincombs:
+        if board[wincomb[0]] == board[wincomb[1]] == board[wincomb[2]] == player1:
+            return 1
+        if board[wincomb[0]] == board[wincomb[1]] == board[wincomb[2]] == player2:
+            return -1
+    if all(cell in {player1, player2} for cell in board):
+        return 0
+
+def askmove(board):
+    for _ in range(3):      # 3 attempts
+        userinput = input('\nWhere do you want to place your x? > ')
+        if userinput in {'1', '2', '3', '4', '5', '6', '7', '8', '9'}:
+            idx = int(userinput) - 1
+            if board[idx] not in {player1, player2}:
+                return idx
+        print('\nInvalid input')
+        return askmove(board)
+    exit(0)
+
+def emptycells(board):
+    for cell in board:
+        if cell not in {player1, player2}:
+            yield cell
+
+def checkposition(board):
+    eval = evaluate(board)
+    if eval is not None:
+        render(board)
+        if eval == 0:
+            print('\nDRAW\n')
+        if eval == 1:
+            print(f'\n{player1} won the game!\n')
+        if eval == -1:
+            print(f'\n{player2} won the game!\n')
+        exit(0)
+
+def minimax(board, ismax, alpha = -float('inf'), beta = float('inf')):
+
+    eval = evaluate(board)
+    if eval is not None:
+        return eval
+    
+    if ismax:
+        bestvalue = -float('inf')
+        for cell in emptycells(board):
+            idx = int(cell) - 1
+            board[idx] = player1
+            minimaxvalue = minimax(board, False, alpha, beta)
+            board[idx] = cell
+            if minimaxvalue > bestvalue:
+                bestvalue = minimaxvalue
+                alpha = max(alpha, bestvalue)
+                if alpha >= beta:
+                    break
+    else:
+        bestvalue = float('inf')
+        for cell in emptycells(board):
+            idx = int(cell) - 1
+            board[idx] = player2
+            minimaxvalue = minimax(board, True, alpha, beta)
+            board[idx] = cell
+            if minimaxvalue < bestvalue:
+                bestvalue = minimaxvalue
+                beta = min(beta, bestvalue)
+                if alpha >= beta:
+                    break
+    return bestvalue
+
+def bestmoves(board, ismax):
+    bestmovelist = []
+    if ismax:
+        bestvalue = -float('inf')
+        for cell in emptycells(board):
+            idx = int(cell) - 1
+            board[idx] = player1
+            minimaxvalue = minimax(board, False)
+            board[idx] = cell
+            if minimaxvalue == bestvalue:
+                bestmovelist.append(cell)
+            elif minimaxvalue > bestvalue:
+                bestvalue = minimaxvalue
+                bestmovelist = [cell]
+    else:
+        bestvalue = float('inf')
+        for cell in emptycells(board):
+            idx = int(cell) - 1
+            board[idx] = player2
+            minimaxvalue = minimax(board, True)
+            board[idx] = cell
+            if minimaxvalue == bestvalue:
+                bestmovelist.append(cell)
+            elif minimaxvalue < bestvalue:
+                bestvalue = minimaxvalue
+                bestmovelist = [cell]
+    return bestmovelist
+    
+import time
+
+if __name__ == '__main__':
+    while True:
+        starttime = time.time()
+        bestmoves_list = bestmoves(board, False)
+        computermove = random.choice(bestmoves_list)
+        exectime = time.time() - starttime
+        print('exectime >', exectime)
+        input()
+        render(board)
+        usermove = askmove(board)
+        board[usermove] = player1
+        checkposition(board)
+        bestmoves_list = bestmoves(board, False)
+        computermove = random.choice(bestmoves_list)
+        idx = int(computermove) - 1
+        board[idx] = player2
+        checkposition(board)
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