HTML输出杨辉三角 

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Yanghui Triangle</title>
</head>

<body>

    <script>
        function print(v) {
            if (typeof v == "number") {
                var w = 30;
                if (n > 30) w = (n - 30) + 40;
                var s = '<span style="padding:4px 2px;display:inline-block;text-align:center;width:' + w + 'px;">' + v + '</span>';
                document.write(s);
            } else {
                document.write(v);
            }
        }
        var n = prompt("请输入幂数：", 9);
        n = n - 0;

        var t1 = new Date();
        var a1 = [1, 1];
        var a2 = [1, 1];
        print('<div style=text-align:center;">');
        for (var i = 0; i <= n; i++) {
            for (var j = 1; j < i + 2; j++) {
                print(c(i, j));
            }
            print("<br />");
        }
        print("</div>");

        var t2 = new Date();
        print("<p style='text-align:center;'>耗时为（毫秒）：" + (t2 - t1) + "</p>");

        function c(x, y) {
            if ((y == 1) || (y == x + 1)) return 1;
            return c(x - 1, y - 1) + c(x - 1, y);
        }


    </script>

</body>

</html>
posted @ 2020-12-29 13:47  艾孜尔江  阅读(445)  评论(0)  编辑  收藏  举报