最近在学习算法方面的知识，看到了一个由算法主导的小游戏，这里给大家分享下代码：
效果：
代码：
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=360px,user-scalable=no" />
<title>2048小游戏</title>
<style>
body,h1,div,table,tr,td{
margin: 0px;
padding: 0px;
}
body{
background-color: rgb(0,0,0);
}
h1{
margin: 36px auto;
text-align: center;
color: rgba(255,255,255,0.7);
font-family: "楷体";
font-size: 48px;
text-shadow: 1px 2px 3px rgb(134,134,134);
}
div{
margin: 12px auto;
line-height: 60px;
}
#box{
margin-top: -24px;
240px;
height: 60px;
text-align: center;
font-weight: bold;
color: rgb(255,255,255);
}
#box input{
border: 3px solid rgb(255,255,255);
border-radius: 4px;
box-shadow: 1px 2px 3px rgb(234,234,234);
}
#box input:focus{
outline-style: none;
}
table{
margin: 24px auto;
border: 3px solid rgb(255,255,255);
border-radius: 6px;
}
#random,td{
60px;
height: 60px;
border: 2px solid rgb(255,255,255);
border-radius: 18px;
text-align: center;
font-weight: bold;
color: rgb(255,255,255);
}
td:hover{
cursor: pointer;
}
</style>
</head>
<body>
<h1>2 0 4 8</h1>
<!-- 显示得分及新游戏按钮 -->
<div id="box">
得分: <span id="span">0</span>
<input id="but" type="button" value="新游戏" />
</div>
<!-- 显示随机数 -->
<div id="random"></div>
<!-- 游戏主要布局 -->
<table border="3px">
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
</table>
</body>
<script type="text/javascript">
var span = document.getElementById("span");
var but = document.getElementById("but");
var td = document.getElementsByTagName("td");
//定义得分
var score = 0;
//定义随机数
var random = document.getElementById("random");
var showNums = [2,4,8,16,32,64,128,256,512,1024];
var showNum = 0;
//定义背景色数组
var colors = ["rgb(255, 169, 182)","rgb(108, 251, 104)","rgb(255, 150, 46)","rgb(255, 121, 46)","rgb(255, 217, 46)",
"rgb(46, 200, 255)","rgb(46, 113, 255)","rgb(240, 46, 255)","rgb(46, 255, 175)","rgb(153, 134, 255)"];
//初始化程序,生成随机数
/* start */
function init(){
var max = maxNum();
var num = 0;
for(var i=4;i > 0;i++){
if(max < Math.pow(2,i+1)){
num = parseInt(Math.random()*i);
break;
}else if(max < 2048){
continue;
}else{
num = parseInt(Math.random()*showNums.length);
break;
}
}
random.innerHTML = showNums[num];
color(random);
showNum = showNums[num];
}
init();
/* end */
//获取棋盘中的最大值
/* start */
function maxNum(){
var max = 0;
for(var i=0;i<td.length;i++){
if(td[i].innerHTML == ""){
max = max;
}else{
if(parseInt(td[i].innerHTML) > max){
max = parseInt(td[i].innerHTML);
}else{
max = max;
}
}
}
return max;
}
/* end */
//根据数字显示背景颜色
/* start */
function color(obj){
for(var i=0;i < colors.length;i++){
if(obj.innerHTML == Math.pow(2,i+1)){
obj.style = "background-color: "+colors[i]+";";
break;
}
}
}
/* end */
//合并算法
/* start */
function offsetTop(obj,index){//合并上
if(index > 3){
if(td[(index-4)].innerHTML == obj.innerHTML){
td[(index-4)].innerHTML = "";
td[(index-4)].style = "background-color: rgba(0, 0, 0, 0);";
return true;
}
}
return false;
}
function offsetBottom(obj,index){//合并下
if(index < 12){
if(td[(index+4)].innerHTML == obj.innerHTML){
td[(index+4)].innerHTML = "";
td[(index+4)].style = "background-color: rgba(0, 0, 0, 0);";
return true;
}
}
return false;
}
function offsetLeft(obj,index){//合并左
if(index!=0 && index!=4 && index!=8 && index!=12){
if(td[(index-1)].innerHTML == obj.innerHTML){
td[(index-1)].innerHTML = "";
td[(index-1)].style = "background-color: rgba(0, 0, 0, 0);";
return true;
}
}
return false;
}
function offsetRight(obj,index){//合并右
if(index!=3 && index!=7 && index!=11 && index!=15){
if(td[(index+1)].innerHTML == obj.innerHTML){
td[(index+1)].innerHTML = "";
td[(index+1)].style = "background-color: rgba(0, 0, 0, 0);";
return true;
}
}
return false;
}
/* end */
//判断单元格是否合并
/* start */
function merge(obj,index){
if(offsetTop(obj,index)){
if(offsetBottom(obj,index)){
if(offsetLeft(obj,index)){
if(offsetRight(obj,index)){
obj.innerHTML = parseInt(obj.innerHTML)*2;//合并上、下、左、右
score += 16;
merge(obj,index);
}else{
obj.innerHTML = parseInt(obj.innerHTML)*2;//仅合并上、下、左
score += 8;
merge(obj,index);
}
}else if(offsetRight(obj,index)){
obj.innerHTML = parseInt(obj.innerHTML)*2;//仅合并上、下、右
score += 8;
merge(obj,index);
}else{
obj.innerHTML = parseInt(obj.innerHTML)*2;//仅合并上、下
score += 4;
merge(obj,index);
}
}else if(offsetLeft(obj,index)){
if(offsetRight(obj,index)){
obj.innerHTML = parseInt(obj.innerHTML)*2;//仅合并上、左、右
score += 8;
merge(obj,index);
}else{
obj.innerHTML = parseInt(obj.innerHTML)*2;//仅合并上、左
score += 4;
merge(obj,index);
}
}else if(offsetRight(obj,index)){
obj.innerHTML = parseInt(obj.innerHTML)*2;//仅合并上、右
score += 4;
merge(obj,index);
}else{
obj.innerHTML = parseInt(obj.innerHTML)*2;//仅合并上
score += 2;
merge(obj,index);
}
}else if(offsetBottom(obj,index)){
if(offsetLeft(obj,index)){
if(offsetRight(obj,index)){
obj.innerHTML = parseInt(obj.innerHTML)*2;//仅合并下、左、右
score += 8;
merge(obj,index);
}else{
obj.innerHTML = parseInt(obj.innerHTML)*2;//仅合并下、左
score += 4;
merge(obj,index);
}
}else if(offsetRight(obj,index)){
obj.innerHTML = parseInt(obj.innerHTML)*2;//仅合并下、右
score += 4;
merge(obj,index);
}else{
obj.innerHTML = parseInt(obj.innerHTML)*2;//仅合并下
score += 2;
merge(obj,index);
}
}else if(offsetLeft(obj,index)){
if(offsetRight(obj,index)){
obj.innerHTML = parseInt(obj.innerHTML)*2;//仅合并左、右
score += 4;
merge(obj,index);
}else{
obj.innerHTML = parseInt(obj.innerHTML)*2;//仅合并左
score += 2;
merge(obj,index);
}
}else if(offsetRight(obj,index)){
obj.innerHTML = parseInt(obj.innerHTML)*2;//仅合并右
score += 2;
merge(obj,index);
}
}
/* end */
//main
/* start */
function gameOver(){
for(var i=0;i<td.length;i++){
if(td[i].innerHTML == ""){
break;
}
if(i == 15){
alert("很遗憾！本局游戏结束。。。");
}
}
}
/* end */
//main
/* start */
(function(){
for(var i=0;i<td.length;i++){
var choose = td[i];
choose.index = i;
choose.onclick = function(){
if(this.innerHTML == ""){
this.innerHTML = showNum;
merge(this,this.index);
if(this.innerHTML >= 2048){
this.innerHTML = "";
this.style = "background-color: rgba(0, 0, 0, 0);";
}
color(this);
init();
}
updateScore();
gameOver();
}
}
})();
/* end */
//更新得分
/* start */
function updateScore(){
if(score > 500){
span.style = "color: rgb(255,0,0)";
}else if(score > 100){
span.style = "color: rgb(255,0,255)";
}else if(score > 50){
span.style = "color: rgb(255,255,0)";
}else if(score > 20){
span.style = "color: rgb(0,0,255)";
}else if(score > 10){
span.style = "color: rgb(0,255,0)";
}
span.innerHTML = score;
}
/* end */
//新游戏
/* start */
but.onclick = function(){
location.reload();
}
/* end */
</script>
</html>