// Created by Wendy Seijas var firstGame = true; $(document).ready(function() { $("body").on("click","#b_again",function() { $("#b_again,#winner").hide(); $("#info").show(); }); $("body").on("click","#b_start",function() { $("#info").hide(); if (firstGame) { startGame(); } else { Game.restartGame(); } }); }); function Game() { this.rows = 6; this.columns = 7; this.status = 0; this.depth = 4; this.score = 100000, this.round = 0; this.winning_array = []; this.iterations = 0; that = this; that.init(); } Game.prototype.init = function() { var game_board = new Array(that.rows); for (var i = 0; i < game_board.length; i++) { game_board[i] = new Array(that.columns); for (j = 0; j < game_board[i].length; j++) { game_board[i][j] = null; } } this.board = new Board(this, game_board, 0); game_board = ""; for (i = 0; i < that.rows; i++) { game_board += ""; for (j = 0; j < that.columns; j++) { game_board += ""; } game_board += ""; } document.getElementById('game_board').innerHTML = game_board; var td = document.getElementById('game_board').getElementsByTagName("td"); for (i = 0; i < td.length; i++) { if (td[i].addEventListener) { td[i].addEventListener('click', that.act, false); } else if (td[i].attachEvent) { td[i].attachEvent('click', that.act); } } }; Game.prototype.act = function(e) { var element = e.target || window.event.srcElement; if (that.round===0) that.place(element.cellIndex); if (that.round==1) that.generateComputerDecision(); }; Game.prototype.place = function(column) { if (that.board.score() != that.score && that.board.score() != -that.score && !that.board.isFull()) { for (var y = that.rows - 1; y >= 0; y--) { if (document.getElementById('game_board').rows[y].cells[column].className == 'empty') { if (that.round == 1) { document.getElementById('game_board').rows[y].cells[column].className = 'checker cpu-checker'; //document.getElementById('game_board').rows[y].cells[column].innerHTML = "

"; } else { document.getElementById('game_board').rows[y].cells[column].className = 'checker human-checker'; //document.getElementById('game_board').rows[y].cells[column].innerHTML = "

"; } break; } } if (!that.board.place(column)) { return alert("Invalid move!"); } that.round = that.switchRound(that.round); that.updateStatus(); } }; Game.prototype.generateComputerDecision = function() { if (that.board.score() != that.score && that.board.score() != -that.score && !that.board.isFull()) { that.iterations = 0; $("#loading").show(); setTimeout(function() { var ai_move = that.maximizePlay(that.board, that.depth); that.place(ai_move[0]); },250); } }; Game.prototype.maximizePlay = function(board, depth) { // Call score of our board var score = board.score(); // Break if (board.isFinished(depth, score)) return [null, score]; // Column, Score var max = [null, -99999]; // For all possible moves for (var column = 0; column < that.columns; column++) { var new_board = board.copy(); // Create new board if (new_board.place(column)) { that.iterations++; // Debug var next_move = that.minimizePlay(new_board, depth - 1); // Recursive calling // Evaluate new move if (max[0]===null || next_move[1] > max[1]) { max[0] = column; max[1] = next_move[1]; } } } $("#loading").hide(); return max; }; Game.prototype.minimizePlay = function(board, depth) { var score = board.score(); if (board.isFinished(depth, score)) return [null, score]; // Column, score var min = [null, 99999]; for (var column = 0; column < that.columns; column++) { var new_board = board.copy(); if (new_board.place(column)) { that.iterations++; var next_move = that.maximizePlay(new_board, depth - 1); if (min[0]===null || next_move[1] < min[1]) { min[0] = column; min[1] = next_move[1]; } } } return min; }; Game.prototype.switchRound = function(round) { // 0 Human, 1 Computer if (round == 0) { return 1; } else { return 0; } } Game.prototype.updateStatus = function() { if (that.board.score() == -that.score) { that.status = 1; that.markWin(); $("#winner").html("YOU HAVE WON!").show(); $("#b_again").show(); } if (that.board.score() == that.score) { that.status = 2; that.markWin(); $("#winner").html("YOU HAVE LOST!").show(); $("#b_again").show(); } if (that.board.isFull()) { that.status = 3; $("#winner").html("IT'S A TIE!").show(); $("#b_again").show(); } } Game.prototype.markWin = function() { document.getElementById('game_board').className = "finished"; for (var i = 0; i < that.winning_array.length; i++) { var name = document.getElementById('game_board').rows[that.winning_array[i][0]].cells[that.winning_array[i][1]].className; document.getElementById('game_board').rows[that.winning_array[i][0]].cells[that.winning_array[i][1]].className = name + " win"; } } Game.prototype.restartGame = function() { var difficulty = document.getElementById('difficulty'); var depth = difficulty.options[difficulty.selectedIndex].value; that.depth = depth; that.status = 0; that.round = 0; that.init(); } function startGame() { firstGame = false; window.Game = new Game(); } // ******** function Board(game, field, player) { this.game = game this.field = field; this.player = player; } Board.prototype.isFinished = function(depth, score) { if (depth == 0 || score == this.game.score || score == -this.game.score || this.isFull()) { return true; } return false; } Board.prototype.place = function(column) { if (this.field[0][column] == null && column >= 0 && column < this.game.columns) { for (var y = this.game.rows - 1; y >= 0; y--) { if (this.field[y][column] == null) { this.field[y][column] = this.player; break; } } this.player = this.game.switchRound(this.player); return true; } else { return false; } } Board.prototype.scorePosition = function(row, column, delta_y, delta_x) { var human_points = 0; var computer_points = 0; this.game.winning_array_human = []; this.game.winning_array_cpu = []; for (var i = 0; i < 4; i++) { if (this.field[row][column] == 0) { this.game.winning_array_human.push([row, column]); human_points++; } else if (this.field[row][column] == 1) { this.game.winning_array_cpu.push([row, column]); computer_points++; } row += delta_y; column += delta_x; } if (human_points == 4) { this.game.winning_array = this.game.winning_array_human; return -this.game.score; } else if (computer_points == 4) { this.game.winning_array = this.game.winning_array_cpu; return this.game.score; } else { return computer_points; } } Board.prototype.score = function() { var points = 0; var vertical_points = 0; var horizontal_points = 0; var diagonal_points1 = 0; var diagonal_points2 = 0; for (var row = 0; row < this.game.rows - 3; row++) { for (var column = 0; column < this.game.columns; column++) { var score = this.scorePosition(row, column, 1, 0); if (score == this.game.score) return this.game.score; if (score == -this.game.score) return -this.game.score; vertical_points += score; } } for (var row = 0; row < this.game.rows; row++) { for (var column = 0; column < this.game.columns - 3; column++) { var score = this.scorePosition(row, column, 0, 1); if (score == this.game.score) return this.game.score; if (score == -this.game.score) return -this.game.score; horizontal_points += score; } } for (var row = 0; row < this.game.rows - 3; row++) { for (var column = 0; column < this.game.columns - 3; column++) { var score = this.scorePosition(row, column, 1, 1); if (score == this.game.score) return this.game.score; if (score == -this.game.score) return -this.game.score; diagonal_points1 += score; } } for (var row = 3; row < this.game.rows; row++) { for (var column = 0; column <= this.game.columns - 4; column++) { var score = this.scorePosition(row, column, -1, +1); if (score == this.game.score) return this.game.score; if (score == -this.game.score) return -this.game.score; diagonal_points2 += score; } } points = horizontal_points + vertical_points + diagonal_points1 + diagonal_points2; return points; } Board.prototype.isFull = function() { for (var i = 0; i < this.game.columns; i++) { if (this.field[0][i] == null) { return false; } } return true; } Board.prototype.copy = function() { var new_board = new Array(); for (var i = 0; i < this.field.length; i++) { new_board.push(this.field[i].slice()); } return new Board(this.game, new_board, this.player); }

My Game