Untitled

<<?php
/*Using the combination of HTML and PHP, implement a web page where the users can upload a text file, exclusively in .txt format, which contains a string of 1000 numbers, such as:*/
//Opening file here
echo <<<_END
    <html>
    <head><title>PHP Form Upload</title></head>
    <body>
    <form method="post" action="assignment4.php" enctype="multipart/form-data">
    Choose a "txt" File and upload it :
    <input type='file' name='filename' size ='1000'>
    <input type="submit" value="Upload"></form>
_END;

	if ($_FILES) {
		if ($_FILES['filename']['type'] == 'text/plain') {
			if (file_exists($_FILES['filename']['tmp_name'])) {
				$string = file_get_contents($_FILES['filename']['tmp_name']);
                $max_product = find_max($string);
               echo "The maximum product of 5 adjacent #s is :" .$max_product[1]. "<br>";
                echo "The five adjacent numbers whose product is ".$max_product[1] ." are " .$max_product[0];
                echo "Factorial of ". $max_product[1]. " is " . $max_product[2];
		}
        else die("File does not exist");
        }
		else die("File is not a text/plain file");
        }


function max_factorial($num)
{
    if($num<=1)
    {
        return 1;
    }
    else
    {
        return $num*max_factorial($num -1);
    }
}
function find_max ($num_str){
     if(strlen($num_str) >1000 || strlen($num_str)<1000){
                    echo "File is not in the correct format!!";
                    }
                else{
                $V =is_numeric($num_str)? true : false;
                if($V ==false){
                    echo "File is not in the correct format!!";
                     var_dump ($V);
                }
                else{
                $currentMax =0;

                for($i =0; $i<995; $i++)
                {
                    $nextMax =1;
                    for ($j=$i; $j<$i+5; $j++)
                    {
                        $nextMax*= $num_str[$j];

                }
                    if($nextMax>$currentMax){
                        $currentMax = $nextMax;
                        $var = substr($num_str, $i, 5);
                    }

			}
                    $remainder =0;
                    $fact =0;
                   for($i = 0; $i<strlen($currentMax) ;$i++)
                   {
                       $remainder = $currentMax%10;
                        $currentMax = (int)$currentMax/10;
                       $fact+= max_factorial($remainder);
                       }
            }
            }
               return array($var,$currentMax, $fact);
            }


function tester (){

}
?>