10-16

<?php

    function dec2hex($str)     {

        $hex = array('0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F');         $hexval = '';         $quotient = $str;         $divisor = $str;         $flag = true;         while($flag)         {

            $len = strlen($divisor);             $pos = 1;             $quotient = 0;             $div = substr($divisor, 0, 2);             $remainder = $div[0];             while($pos < $len)             {

                $div = $remainder == 0 ? $divisor[$pos] : $remainder.$divisor[$pos];                 $remainder = $div % 16;                 $quotient = $quotient.floor($div/16);                 $pos++;             }             $quotient = trim_left_zeros($quotient);             $divisor = "$quotient";             $hexval = $hex[$remainder].$hexval;             if (strlen($divisor)<=2)             {

                if ($divisor<15)                 {

                    $flag = false;                 }             }         }         $hexval = $hex[$quotient].$hexval;         $hexval = trim_left_zeros($hexval);         return $hexval;     }     function trim_left_zeros($str)     {

        $str = ltrim($str, '0');         if (empty($str))         {

            $str = '0';         }         return $str;     }          $hex = dec2hex('10153302696068');     if($hex%2!=0) $hex = '0'. $hex;     $str = str_split($hex,2);     $out = '';     for($i=0;$i<count($str);$i++)     {

      $out = '\x' . $str[$i] . $out;     }     $out = $out.'\x00\00';     echo $out;     

?>

16-10

<?php

function convBase($numberInput, $fromBaseInput, $toBaseInput) {     if ($fromBaseInput==$toBaseInput) return $numberInput;     $fromBase = str_split($fromBaseInput,1);     $toBase = str_split($toBaseInput,1);     $number = str_split($numberInput,1);     $fromLen=strlen($fromBaseInput);     $toLen=strlen($toBaseInput);     $numberLen=strlen($numberInput);     $retval='';     if ($toBaseInput == '0123456789')     {         $retval=0;         for ($i = 1;$i <= $numberLen; $i++)             $retval = bcadd($retval, bcmul(array_search($number[$i-1], $fromBase),bcpow($fromLen,$numberLen-$i)));         return $retval;     }     if ($fromBaseInput != '0123456789')         $base10=convBase($numberInput, $fromBaseInput, '0123456789');     else         $base10 = $numberInput;     if ($base10<strlen($toBaseInput))         return $toBase[$base10];     while($base10 != '0')     {         $retval = $toBase[bcmod($base10,$toLen)].$retval;         $base10 = bcdiv($base10,$toLen,0);     }     return $retval; } $btime = microtime(true); echo convBase('c4ca4238a0b923820dcc509a6f75849b', '0123456789abcdef', '0123456789'); echo microtime(true) - $btime; ?>