用PHP实现小写金额转换大写金额【精确到分】

/**
    *数字金额转换成中文大写金额的函数
    *String Int  $num  要转换的小写数字或小写字符串
    *return 大写字母
    *小数位为两位
    **/
    function get_amount($num){
        $c1 = "零壹贰叁肆伍陆柒捌玖";
        $c2 = "分角元拾佰仟万拾佰仟亿";
        $num = round($num, 2);
        $num = $num * 100;
        if (strlen($num) > 10) {
            return "数据太长，没有这么大的钱吧，检查下";
        } 
        $i = 0;
        $c = "";
        while (1) {
            if ($i == 0) {
                $n = substr($num, strlen($num)-1, 1);
            } else {
                $n = $num % 10;
            } 
            $p1 = substr($c1, 3 * $n, 3);
            $p2 = substr($c2, 3 * $i, 3);
            if ($n != '0' || ($n == '0' && ($p2 == '亿' || $p2 == '万' || $p2 == '元'))) {
                $c = $p1 . $p2 . $c;
            } else {
                $c = $p1 . $c;
            } 
            $i = $i + 1;
            $num = $num / 10;
            $num = (int)$num;
            if ($num == 0) {
                break;
            } 
        }
        $j = 0;
        $slen = strlen($c);
        while ($j < $slen) {
            $m = substr($c, $j, 6);
            if ($m == '零元' || $m == '零万' || $m == '零亿' || $m == '零零') {
                $left = substr($c, 0, $j);
                $right = substr($c, $j + 3);
                $c = $left . $right;
                $j = $j-3;
                $slen = $slen-3;
            } 
            $j = $j + 3;
        } 
 
        if (substr($c, strlen($c)-3, 3) == '零') {
            $c = substr($c, 0, strlen($c)-3);
        }
        if (empty($c)) {
            return "零元整";
        }else{
            return $c . "整";
        }
    }