javascript 机试题—蛇形数字

在论坛上看到一个javascript的机试题，自己试着写了写，基本上实现了题目的要求：

有条蛇它长度不固定，蛇头朝北顺时针盘旋着，请打印出如下图的蛇形矩阵。答题时间40分钟。
9  9  9  9  9  9  9
8  6  6  6  6  6  9
8  6  3  3  4  7  9
8  5  3  1  4  7
8  5  2  2  4  7
8  5  5  5  4  7
8  8  8  7  7  7

 

源代码：

•  
  • <html xmlns=" http://www.w3.org/1999/xhtml" >
    <head runat="server">
        <title>无标题页</title>
        <script language="javascript" type="text/javascript">
            var maxNum=9;
            var maxRow=7;
            var maxCol=7;
            var $get=document.getElementById;
            function initTable()
            {
                var tr=null;
                var td=null;
                var table=null;
                var tbody=null;
                table=document.createElement("table");
                //table=$get("table");
                tbody=document.createElement("tbody");
                //tbody=$get("newbody");
                table.id="table_1";
                table.style.display="block";
                table.width="200px";
                table.height="200px";
                table.border=1;
                for(var rI=1;rI<=7;rI++)
                {
                    tr=document.createElement("tr");
                    tr.id="tr"+rI;
                    for(var colI=1;colI<=7;colI++)
                    {
                        td=document.createElement("td");
                        td.id="td"+rI+""+colI;
                        tr.appendChild(td);
                    }
                    tbody.appendChild(tr);
                }
                table.appendChild(tbody);
                document.body.appendChild(table);
                //alert($get("table_1"));
            }
            function fillData()
            {
                var table=null;
                var num=1;
                var numIndex=1;
                var de=1;
                var startRow=4;
                var startCol=4;
                var rowIndex=startRow;
                var colIndex=startCol;
                var cell=null;
                var dnumIndex=0;
                var dMaxnum=1;
                var span=null;
                for(num=1;num<=9;num++)
                {
                    for(numIndex=1;numIndex<=num;numIndex++)
                    {
                        cell=$get("td"+rowIndex+""+colIndex);
                        //alert(rowIndex+""+colIndex+document.getElementById("td"+rowIndex+""+colIndex));
                        cell.appendChild(document.createTextNode(num+""));
                        //alert("de:"+de+"---rowIndex:"+rowIndex+"---colIndex:"+colIndex+"---dnumIndex:"+dnumIndex+"---num:"+num);
                        dnumIndex++;
                        if(dnumIndex>=dMaxnum)
                        {
                            de=(de+1)%4;
                            dnumIndex=1;
                            if(de%2==0)
                                dMaxnum++;
                        }
                        switch(de)
                        {
                            case 0:
                                rowIndex--;
                                break;
                            case 1:
                                colIndex++;
                                break;
                            case 2:
                                rowIndex++;
                                break;
                            case 3:
                                colIndex--;
                                break;
                            default:
                                break;
                        }
                        //alert("de:"+de+"---rowIndex:"+rowIndex+"---colIndex:"+rowIndex+"---dnumIndex:"+dnumIndex);
                    }
                }
            }
        </script>
    </head>
    <body>
        <form id="form1" runat="server">
        <div id="s">
        </div>
        </form>
        <script language="javascript">
            //init();
            initTable();
            fillData()
        </script>
    </body>
    </html>
    
    
  • 长度不限制，程序可以稍作修改，通过传入的参数动态生成。
• 
  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" " http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">