一、前言

之前做了一个算法作业，叫做棋盘覆盖，本来需要用c语言来编写的，但是因为我的c语言是半桶水（哈哈），所以索性就把网上的c语言写法改成JavaScript写法，并且把它的覆盖效果显示出来

二、关键代码

<!DOCTYPE html>

<html>

<head>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

<title>算法作业2</title>

<style type="text/css">

    #num{}

    #chess{

        margin-top:20px;

        }

</style>

</head>

<body>

    <div id="num">

        <p>设置棋盘大小：

            <input type="text" name="Num" size="4" />

        </p>

        <p>请输入特殊方格的位置：</p>

        <p>

        x:<input type="text" name="X" size="25"/><br />

        y:<input type="text" name="Y" size="25" />

        </p>

        <p>

            <input type="button" value="设置棋盘参数" />

            <input type="button" value="生成棋盘" />

        </p>

    </div>

    <div id="chess">

    </div>

</body>

</html>

<script type="text/javascript">

    window.onload=function()

    {//棋盘设置

        var chess=document.getElementById('chess');

        var input=document.getElementsByTagName('input')[3];

        input.onclick=function()

        {

            var N=document.getElementsByTagName('input')[0].value;

            var table=document.createElement('table');

            chess.appendChild(table);

            table.style.border='2px solid';

                table.style.borderCollapse='collapse';

            for(var i=0;i<N;i++)

            {

                var tr=document.createElement('tr');

                table.appendChild(tr);

                tr.style.height = "20px";

                tr.style.border='1px solid #ccc';

                for(var j=0;j<N;j++)

                {

                    var td=document.createElement('td');

                    tr.appendChild(td);

                    td.style.width = "20px";

                    td.style.border='1px solid #ccc';

                }

            }    

        }

        var Out=document.getElementsByTagName('input')[4];

        var  Matrix =  new Array();

        for(var i=0;i<100; i++)

        {  //初始化棋盘矩阵

               Matrix[i] = new Array();

               for(var j=0;j<100;j++)

            {

                  Matrix[i][j]=0;

               }

        }

        Out.onclick=function()

        {  //棋盘生成

            var r,c;

            var X=document.getElementsByTagName('input')[1].value;

            var Y=document.getElementsByTagName('input')[2].value;

            var N=document.getElementsByTagName('input')[0].value;

            chessBoard(0,0,X-1,Y-1,N);

            for (r = 0; r < N; r++)

            {

                for (c = 0; c < N; c++)

                {

                     var q=Matrix[r][c];

                     var table=document.getElementsByTagName('table')[0];

                     table.rows[r].cells[c].style.background='rgb('+13*q%256+','+43*q%256+','+73*q%256+')';

                }

            }

        }

        var nCount = 0;

        function chessBoard(tr,tc,dr,dc,size)

        {

            var s,t;

            if (size == 1) return;

            s =size/2;

            t = ++nCount ;

            if (dr < tr + s && dc < tc +s)

                chessBoard(tr,tc,dr,dc,s);

            else

            {

                Matrix[tr+s-1][tc+s-1] = t;

                chessBoard(tr,tc,tr+s-1,tc+s-1,s);

            }

            if (dr < tr + s && dc >= tc + s )

                chessBoard(tr,tc+s,dr,dc,s);

            else

            {

                Matrix[tr+s-1][tc+s] = t;

                chessBoard(tr,tc+s,tr+s-1,tc+s,s);

            }

            if (dr >= tr + s && dc < tc + s)

                chessBoard(tr+s,tc,dr,dc,s);

            else

            {

                Matrix[tr+s][tc+s-1] = t;

                chessBoard(tr+s,tc,tr+s,tc+s-1,s);

            }

            if (dr >= tr + s && dc >= tc + s)

                chessBoard(tr+s,tc+s,dr,dc,s);

            else

            {

                Matrix[tr+s][tc+s] = t;

                chessBoard(tr+s,tc+s,tr+s,tc+s,s);

            }

        }

    }

</script>