tic-tac-toe_alpha_beta_pruning.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 1,
   "id": "e8d79854",
   "metadata": {},
   "outputs": [],
   "source": [
    "board = dict()\n",
    "for i in range(1,10):\n",
    "    board[i] = '_'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "9d278bed",
   "metadata": {},
   "outputs": [],
   "source": [
    "def print_board():\n",
    "    print(f\"{board[1]}  |  {board[2]}  |  {board[3]}\\t\\t\\t1,2,3\\n\")\n",
    "    print(f\"{board[4]}  |  {board[5]}  |  {board[6]}\\t\\t\\t4,5,6\\n\")\n",
    "    print(f\"{board[7]}  |  {board[8]}  |  {board[9]}\\t\\t\\t7,8,9\\n\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "207fe21e",
   "metadata": {},
   "outputs": [],
   "source": [
    "def win(mark):\n",
    "    win=0\n",
    "    if (board[1]==board[2]) & (board[2]==board[3]) & (board[3]==mark):\n",
    "        win=1\n",
    "    if (board[4]==board[5]) & (board[5]==board[6]) & (board[6]==mark):\n",
    "        win=1\n",
    "    if (board[7]==board[8]) & (board[8]==board[9]) & (board[9]==mark):\n",
    "        win=1\n",
    "        \n",
    "    if (board[1]==board[4]) & (board[4]==board[7]) & (board[7]==mark):\n",
    "        win=1\n",
    "    if (board[2]==board[5]) & (board[5]==board[8]) & (board[8]==mark):\n",
    "        win=1\n",
    "    if (board[3]==board[6]) & (board[6]==board[9]) & (board[9]==mark):\n",
    "        win=1\n",
    "        \n",
    "        \n",
    "    if (board[1]==board[5]) & (board[5]==board[9]) & (board[9]==mark):\n",
    "        win=1\n",
    "    if (board[3]==board[5]) & (board[5]==board[7]) & (board[7]==mark):\n",
    "        win=1\n",
    "    if win==1:\n",
    "        return True\n",
    "    else:\n",
    "        return False"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "19f8333c",
   "metadata": {},
   "outputs": [],
   "source": [
    "def player_move(p_mark):\n",
    "    p = int(input('\\nenter the place to mark : '))\n",
    "    print()\n",
    "    if (p>=1) & (p<=9):\n",
    "        if board[p]=='_':\n",
    "            board[p] = p_mark\n",
    "        else:\n",
    "            print('\\nalready filled\\n')\n",
    "            player_move(p_mark)\n",
    "    else:\n",
    "        print('\\nenter value between 1 to 9\\n')\n",
    "        player_move(p_mark)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "id": "84e986cc",
   "metadata": {},
   "outputs": [],
   "source": [
    "def is_full():\n",
    "    draw = True\n",
    "    for i in range(1,10):\n",
    "        if board[i]=='_':\n",
    "            draw = False\n",
    "    if draw == True:\n",
    "        return True\n",
    "    else:\n",
    "        return False"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "id": "e1340d6c",
   "metadata": {},
   "outputs": [],
   "source": [
    "def computer_move(c_mark):\n",
    "    global count\n",
    "    count = 0\n",
    "    best_score = -100\n",
    "    move = 0\n",
    "    for i in range(1,10):\n",
    "        if board[i]=='_':\n",
    "            board[i]=c_mark\n",
    "            score = minimax(board,0,False,-100,100)\n",
    "            if score>best_score:\n",
    "                best_score=score\n",
    "                move=i\n",
    "            board[i]='_'\n",
    "    board[move] = c_mark\n",
    "    return"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "id": "b9a1b03b",
   "metadata": {},
   "outputs": [],
   "source": [
    "def  minimax(board,depth,ismaximize,alpha,beta):\n",
    "    global count\n",
    "    c_mark = 'o'\n",
    "    p_mark = 'x'\n",
    "    if win(c_mark):\n",
    "        count = count + 1\n",
    "        return 10 - depth\n",
    "    elif win(p_mark):\n",
    "        count = count + 1\n",
    "        return -10 + depth\n",
    "    elif is_full():\n",
    "        count = count + 1\n",
    "        return 0\n",
    "    if ismaximize:\n",
    "        best_score = -100\n",
    "        for i in range(1,10):\n",
    "            if board[i]=='_':\n",
    "                board[i]=c_mark\n",
    "                score = minimax(board,depth+1,False,alpha,beta)\n",
    "                if score>best_score:\n",
    "                    best_score=score\n",
    "                board[i]='_'\n",
    "                alpha = max(alpha,score)\n",
    "                if alpha>=beta:\n",
    "                    break\n",
    "        return best_score\n",
    "    else:\n",
    "        best_score = 100\n",
    "        for i in range(1,10):\n",
    "            if board[i]=='_':\n",
    "                board[i]=p_mark\n",
    "                score = minimax(board,depth+1,True,alpha,beta)\n",
    "                if score<best_score:\n",
    "                    best_score=score\n",
    "                board[i]='_'\n",
    "                beta = min(beta,score)\n",
    "                if alpha>=beta:\n",
    "                    break\n",
    "        return best_score"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "id": "ba7287c6",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "\n",
      "count : 14113\n",
      "\n",
      "o  |  _  |  _\t\t\t1,2,3\n",
      "\n",
      "_  |  _  |  _\t\t\t4,5,6\n",
      "\n",
      "_  |  _  |  _\t\t\t7,8,9\n",
      "\n",
      "\n",
      "enter the place to mark : 2\n",
      "\n",
      "\n",
      "count : 1101\n",
      "\n",
      "o  |  x  |  _\t\t\t1,2,3\n",
      "\n",
      "o  |  _  |  _\t\t\t4,5,6\n",
      "\n",
      "_  |  _  |  _\t\t\t7,8,9\n",
      "\n",
      "\n",
      "enter the place to mark : 7\n",
      "\n",
      "\n",
      "count : 61\n",
      "\n",
      "o  |  x  |  _\t\t\t1,2,3\n",
      "\n",
      "o  |  o  |  _\t\t\t4,5,6\n",
      "\n",
      "x  |  _  |  _\t\t\t7,8,9\n",
      "\n",
      "\n",
      "enter the place to mark : 9\n",
      "\n",
      "\n",
      "count : 5\n",
      "\n",
      "o  |  x  |  _\t\t\t1,2,3\n",
      "\n",
      "o  |  o  |  o\t\t\t4,5,6\n",
      "\n",
      "x  |  _  |  x\t\t\t7,8,9\n",
      "\n",
      "computer won\n"
     ]
    }
   ],
   "source": [
    "for i in range(1,10):\n",
    "    board[i] = '_'\n",
    "def play():\n",
    "    c_mark = 'o'\n",
    "    p_mark = 'x'\n",
    "    while(not is_full()):\n",
    "        computer_move(c_mark)\n",
    "        print(f'\\ncount : {count}\\n')\n",
    "        print_board()\n",
    "        if win(c_mark):\n",
    "            print('computer won')\n",
    "            break;\n",
    "        if is_full():\n",
    "            print('match draw')\n",
    "            break;\n",
    "        player_move(p_mark)\n",
    "        if win(p_mark):            \n",
    "            print('player won')\n",
    "            break;\n",
    "        if is_full():\n",
    "            print('match draw')\n",
    "            break;\n",
    "play()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "id": "dabc57b7",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "_  |  _  |  _\t\t\t1,2,3\n",
      "\n",
      "_  |  _  |  _\t\t\t4,5,6\n",
      "\n",
      "_  |  _  |  _\t\t\t7,8,9\n",
      "\n",
      "\n",
      "enter the place to mark : 9\n",
      "\n",
      "\n",
      "count : 3561\n",
      "\n",
      "_  |  _  |  _\t\t\t1,2,3\n",
      "\n",
      "_  |  o  |  _\t\t\t4,5,6\n",
      "\n",
      "_  |  _  |  x\t\t\t7,8,9\n",
      "\n",
      "\n",
      "enter the place to mark : 1\n",
      "\n",
      "\n",
      "count : 222\n",
      "\n",
      "x  |  o  |  _\t\t\t1,2,3\n",
      "\n",
      "_  |  o  |  _\t\t\t4,5,6\n",
      "\n",
      "_  |  _  |  x\t\t\t7,8,9\n",
      "\n",
      "\n",
      "enter the place to mark : 8\n",
      "\n",
      "\n",
      "count : 19\n",
      "\n",
      "x  |  o  |  _\t\t\t1,2,3\n",
      "\n",
      "_  |  o  |  _\t\t\t4,5,6\n",
      "\n",
      "o  |  x  |  x\t\t\t7,8,9\n",
      "\n",
      "\n",
      "enter the place to mark : 3\n",
      "\n",
      "\n",
      "count : 2\n",
      "\n",
      "x  |  o  |  x\t\t\t1,2,3\n",
      "\n",
      "_  |  o  |  o\t\t\t4,5,6\n",
      "\n",
      "o  |  x  |  x\t\t\t7,8,9\n",
      "\n",
      "\n",
      "enter the place to mark : 4\n",
      "\n",
      "match draw\n"
     ]
    }
   ],
   "source": [
    "for i in range(1,10):\n",
    "    board[i] = '_'\n",
    "def play():\n",
    "    c_mark = 'o'\n",
    "    p_mark = 'x'\n",
    "    print_board()\n",
    "    while(not is_full()):\n",
    "        player_move(p_mark)\n",
    "        if win(p_mark):            \n",
    "            print('player won')\n",
    "            break;\n",
    "        if is_full():\n",
    "            print('match draw')\n",
    "            break;\n",
    "        computer_move(c_mark)\n",
    "        print(f'\\ncount : {count}\\n')\n",
    "        print_board()\n",
    "        if win(c_mark):\n",
    "            print('computer won')\n",
    "            break;\n",
    "        if is_full():\n",
    "            print('match draw')\n",
    "            break;\n",
    "play()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "c05bca10",
   "metadata": {},
   "outputs": [],
   "source": []
  }
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