利用JavaScript在网页实现八数码启发式A*算法动画效果

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>八数码</title>
 <style type="text/css">
 #result input{
  display: inline-block;
  font-family:"微软雅黑";
  font-size: 60px;
  font-weight: 900;
  text-align: center;
  width:100px;
  height:100px;
  background:url(images/0.png);
  background-size:cover;
 }
</style>
</head>
<body>
 <div id="result">
  <input type="text" id="r1">
  <input type="text" id="r2">
  <input type="text" id="r3"><br>
  <input type="text" id="r4">
  <input type="text" id="r5">
  <input type="text" id="r6"><br>
  <input type="text" id="r7">
  <input type="text" id="r8">
  <input type="text" id="r9"><br>
 </div>
 <button onclick="run()">求解</button>
</body>
</html>

var startArray=[[8,1,3],[0,2,4],[7,6,5]];//初始化八数码数组
   //获取输入的初始状态
   var cpic=1;
   for(var i=0;i<N;i++){
    for(var j=0;j<N;j++){
     var rid='r'+cpic++;
     var inputValue=getId(rid).value;
     if(inputValue==""){inputValue=0;}
     startArray[i][j]=parseInt(inputValue);
     getId(rid).value="";
    }
   }
var startGraph=new Graph(startArray);
var endArray=[[ 1,2,3],[ 8,0,4 ],[ 7,6,5 ]];
var endGraph=new Graph(endArray);//目标节点
evaluateGraph(startGraph,endGraph);
showGraph(startGraph);

//节点类
  var Graph = function(formData){
   this.form=formData;
   this.evalue=0;
   this.udirect=0;
   this.parent=null;
  };

function showGraph(graph) {
   var c=1;
   for(var i=0;i<N;i++){
    for(var j=0;j<N;j++){
     var s='r'+c++;
     getId(s).style.backgroundImage="url(images/"+graph.form[i][j]+".png)";
    }
   }
  }

//评估函数
  function evaluateGraph(theGraph, endGraph){
   var differ = 0;//差距数
   for (var i = 0; i<N; i++)
   {
    for (var j = 0; j<N; j++)
    {
     if (theGraph.form[i][j] != endGraph.form[i][j]){differ++;}
    }
   }
   theGraph.evalue = differ;
   return differ;
  }

//移动数码组
  function moveGraph(theGraph, direct){
   var HasGetBlank = 0;//是否找到空格位置
   var AbleMove = 1;//是否可移动
   var i, j, t_i, t_j;
   //查找空格坐标i,j
   for (i = 0; i<N; i++)
   {
    for (j = 0; j<N; j++)
    {
     if (theGraph.form[i][j] == 0)
     {
      HasGetBlank = 1;
      break;
     }
    }
    if (HasGetBlank == 1)
     break;
   }
   t_i = i;
   t_j = j;
   //移动空格
   switch (direct)
   {
    case 1://上
     t_i--;
     if (t_i<0)
      AbleMove = 0;//移动超过边界
     break;
    case 2://下
     t_i++;
     if (t_i >= N)
      AbleMove = 0;
     break;
    case 3://左
     t_j--;
     if (t_j<0)
      AbleMove = 0;
     break;
    case 4://右
     t_j++;
     if (t_j >= N)
      AbleMove = 0;
     break;
   }
   //Direct方向不能移动，返回原节点
   if (AbleMove == 0)
   {
    return theGraph;
   }
   //向Direct方向移动，生成新节点
   var ta=[[0,0,0],[0,0,0],[0,0,0]];
   var New_graph = new Graph(ta);
   for (var x = 0; x<N; x++)//复制数码组
   {
    for (var y = 0; y<N; y++)
    {
     New_graph.form[x][y] = theGraph.form[x][y];
    }
   }
   //交换
   New_graph.form[i][j] = New_graph.form[t_i][t_j];//交换空格和移动方向上的数字
   New_graph.form[t_i][t_j] = 0;
   return New_graph;
  }

//搜索路径
  function Search(beginGraph, endGraph){
   var g1, g2, g;
   var Step = 0;//深度
   var Direct = 0;//方向
   var i;
   var front=-1,rear=-1;
   g1=beginGraph;//初始八数码节点
   while (g1)//队列不空,从close队列中拿出一个节点
   {
    for (i = 1; i <= 4; i++){//分别从四个方向推导出新子节点
     Direct = i;
     if (Direct == g1.udirect)
      continue;//跳过屏蔽方向
     g2=moveGraph(g1,Direct);
     if (evaluateGraph(g2,g1)!=0){//数码组是否可以移动
      evaluateGraph(g1,endGraph);
      evaluateGraph(g2,endGraph);//评价新的节点
      if (g2.evalue <= g1.evalue + 1)//利用评估值判断是否为优越节点
      { //若为优，将g2的父节点指向g1
       g2.parent = g1;
       //设置屏蔽方向，防止往回推
       switch (Direct){
        case 1://上
         g2.udirect = 2;
         break;
        case 2://下
         g2.udirect = 1;
         break;
        case 3://左
         g2.udirect = 4;
         break;
        case 4://右
         g2.udirect = 3;
         break;
       }
       Qu[++rear]=g2;//把优越节点放到close队列
       if (g2.evalue == 0)//为0则搜索完成
       {
        g = g2;
        break;
       }
      }
      else{g2 = null;}//抛弃劣质节点
     }
    }
    //搜索完成，继续退出
    if (typeof g !== 'undefined')
    {
     if (g.evalue == 0)
     {
      break;
     }
    }
    Step++;//统计深度
    if (Step>Max_Step){
     alert("超过搜索深度！");
     break;}
    g1=Qu[++front];//从close队列中拿出一个节点继续下一轮展开
   }
   return g;
  }

var top=-1;
   var G;
   G = Search(startGraph, endGraph);
   //解序列存入堆栈
   var P=G;
   while (P != null)
   {
    top++;
    St[top] = P;
    P = P.parent;
   }
   //动画执行
   var si=setInterval(function () {
    if (top>-1)
    {
     showGraph(St[top]);
     top--;
    }else {
     clearInterval(si);
    }
   },1000);
  }