写一个2048游戏不难，通过分析你发现主要问题是如何根据当前状态和滑动方向，确定出下一个方格状态即滑动后的结果(不考虑新加入的随机方格)。每个状态绘制出来便成了一个简单的2048游戏。
输入
输入数据有多组，每组数据的第一行为一个整数d（0表示向左滑，1表示向右滑，2表示向上滑，3表示向下滑）。
接下来有4行4列的方格，每个方格的值只能为0，2，4，8，16，32，64，128，256，512，1024，2048，其中0表示该格子为空白。
输出
每组输出滑动后的状态，即4行4列的格子值。
样例输入
2
0 0 0 0
0 0 0 0
0 2 2 0
2 0 0 0
0
2 2 2 0
0 0 2 0
0 0 0 0
0 0 0 0
样例输出
2 2 2 0
0 0 0 0
0 0 0 0
0 0 0 0
4 2 0 0
2 0 0 0
0 0 0 0
0 0 0 0
基本的算法是，如果2^k是最大的数字，那么我们努力将2^(k-1)放在它的旁边，然后再把2^(k-2)放在2^(k-1)的旁边，以此类推。
为了达成这一点，我们努力将最大的数字放在角落，然后将第二大的数字放在它旁边，以此类推。将最大的数字放在角落，这样就可以留出足够的空间来组合出更大的数字。
最终我们期望形成这样的图形：
x x x x
4 2 x x
8 16 32 64
1024 512 256 128
html
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>2048</title>
<link rel="stylesheet" type="text/css" href="css/2048.css" />
<!-- <script type="text/javascript" src="http://code.jquery.com/jquery-latest.js"></script> -->
<script type="text/javascript" src="js/2048.js"></script>
</head>
<body>
<div id="div2048">
<a id="start">tap to start :-)</a>
</div>
</body>
</html>
@charset "utf-8"; #div2048 { width: 500px; height: 500px; background-color: #b8af9e; margin: 0 auto; position: relative; } #start { width: 500px; height: 500px; line-height: 500px; display: block; text-align: center; font-size: 30px; background: #f2b179; color: #FFFFFF; } #div2048 div.tile { margin: 20px 0px 0px 20px; width: 100px; height: 40px; padding: 30px 0; font-size: 40px; line-height: 40px; text-align: center; float: left; } #div2048 div.tile0{ background: #ccc0b2; } #div2048 div.tile2 { color: #7c736a; background: #eee4da; } #div2048 div.tile4 { color: #7c736a; background: #ece0c8; } #div2048 div.tile8 { color: #fff7eb; background: #f2b179; } #div2048 div.tile16 { color:#fff7eb; background:#f59563; } #div2048 div.tile32 { color:#fff7eb; background:#f57c5f; } #div2048 div.tile64 { color:#fff7eb; background:#f65d3b; } #div2048 div.tile128 { color:#fff7eb; background:#edce71; } #div2048 div.tile256 { color:#fff7eb; background:#edcc61; } #div2048 div.tile512 { color:#fff7eb; background:#ecc850; } #div2048 div.tile1024 { color:#fff7eb; background:#edc53f; } #div2048 div.tile2048 { color:#fff7eb; background:#eec22e; }
2048.js
function game2048(container) { this.container = container; this.tiles = new Array(16); } game2048.prototype = { init: function(){ for(var i = 0, len = this.tiles.length; i < len; i++){ var tile = this.newTile(0); tile.setAttribute('index', i); this.container.appendChild(tile); this.tiles[i] = tile; } this.randomTile(); this.randomTile(); }, newTile: function(val){ var tile = document.createElement('div'); this.setTileVal(tile, val) return tile; }, setTileVal: function(tile, val){ tile.className = 'tile tile' + val; tile.setAttribute('val', val); tile.innerHTML = val > 0 ? val : ''; }, randomTile: function(){ var zeroTiles = []; for(var i = 0, len = this.tiles.length; i < len; i++){ if(this.tiles[i].getAttribute('val') == 0){ zeroTiles.push(this.tiles[i]); } } var rTile = zeroTiles[Math.floor(Math.random() * zeroTiles.length)]; this.setTileVal(rTile, Math.random() < 0.8 ? 2 : 4); }, move:function(direction){ var j; switch(direction){ case 'W': for(var i = 4, len = this.tiles.length; i < len; i++){ j = i; while(j >= 4){ this.merge(this.tiles[j - 4], this.tiles[j]); j -= 4; } } break; case 'S': for(var i = 11; i >= 0; i--){ j = i; while(j <= 11){ this.merge(this.tiles[j + 4], this.tiles[j]); j += 4; } } break; case 'A': for(var i = 1, len = this.tiles.length; i < len; i++){ j = i; while(j % 4 != 0){ this.merge(this.tiles[j - 1], this.tiles[j]); j -= 1; } } break; case 'D': for(var i = 14; i >= 0; i--){ j = i; while(j % 4 != 3){ this.merge(this.tiles[j + 1], this.tiles[j]); j += 1; } } break; } this.randomTile(); }, merge: function(prevTile, currTile){ var prevVal = prevTile.getAttribute('val'); var currVal = currTile.getAttribute('val'); if(currVal != 0){ if(prevVal == 0){ this.setTileVal(prevTile, currVal); this.setTileVal(currTile, 0); } else if(prevVal == currVal){ this.setTileVal(prevTile, prevVal * 2); this.setTileVal(currTile, 0); } } }, equal: function(tile1, tile2){ return tile1.getAttribute('val') == tile2.getAttribute('val'); }, max: function(){ for(var i = 0, len = this.tiles.length; i < len; i++){ if(this.tiles[i].getAttribute('val') == 2048){ return true; } } }, over: function(){ for(var i = 0, len = this.tiles.length; i < len; i++){ if(this.tiles[i].getAttribute('val') == 0){ return false; } if(i % 4 != 3){ if(this.equal(this.tiles[i], this.tiles[i + 1])){ return false; } } if(i < 12){ if(this.equal(this.tiles[i], this.tiles[i + 4])){ return false; } } } return true; }, clean: function(){ for(var i = 0, len = this.tiles.length; i < len; i++){ this.container.removeChild(this.tiles[i]); } this.tiles = new Array(16); } } var game, startBtn; window.onload = function(){ var container = document.getElementById('div2048'); startBtn = document.getElementById('start'); startBtn.onclick = function(){ this.style.display = 'none'; game = game || new game2048(container); game.init(); } } window.onkeydown = function(e){ var keynum, keychar; if(window.event){ // IE keynum = e.keyCode; } else if(e.which){ // Netscape/Firefox/Opera keynum = e.which; } keychar = String.fromCharCode(keynum); if(['W', 'S', 'A', 'D'].indexOf(keychar) > -1){ if(game.over()){ game.clean(); startBtn.style.display = 'block'; startBtn.innerHTML = 'game over, replay?'; return; } game.move(keychar); } }