Write a function GeneratePassword which accepts two arguments, an integer and a character string consisting of letters (a-z) and digits (0-9).

When GeneratePassword(5,'abc0123') is called, it should return a random string of 5 characters taken from 'abc0123'.



For Example : GeneratePassword(7,'abczxc012394') could return any of the following outputs :
2c00acb
2c23z93
030b2a4

function GeneratePassword($length, $characters)

      {

      if ($characters == '')

      {

      return '';

      }

      $chars_length = strlen($characters)-1;

      while(strlen($pwd) <= $length)

      {

      $rand_char = mt_rand(0, $chars_length);

      $pwd .= $characters[$rand_char];

      }

      return $pwd;

      }

Create a function named 'sortsalary' which will accept an XML string as input. The XML string contains the data related to employees of the company. The following is the structure of the XML string.

<employees><employee empid="1" empname="Rock" empsalary="345" /><employee empid="2" empname="Jim" empsalary="500" /><employee empid="3" empname="Rick" empsalary="600" /></employees>

You are required to sort the employee's salary in decreasing order and display the name along with the salary in pairs separated by a hyphen (-). All records must be comma separated.

Here is an example. Suppose the above mentioned XML string is passed to the function 'sortsalary' in the following manner:

$a = '<employees><employee empid="1" empname="Rock" empsalary="345" /><employee empid="2" empname="Jim" empsalary="500" /><employee empid="3" empname="Rick" empsalary="600" /></employees>';

sortsalary($a);

Then the function should display the following output:

Rick-600,Jim-500,Rock-345

function sortsalary($a)
{
	$xmlstr=$a;
	$xml = simplexml_load_string($xmlstr);
	$recordcount = count($xml->employee);
	$salary = array();
	$str_output="";
	for ($i=0; $i<$recordcount; $i++)
	{
		$salary[] =$xml->employee[$i]["empsalary"];
	}
	rsort($salary,SORT_NUMERIC);
	$arraycount  = count($salary);
for($j=0;$j<$arraycount;$j++)
{
for ($i=0; $i<$recordcount; $i++)
{
	if ($xml->employee[$i]["empsalary"]==$salary[$j])
	{
		if ($str_output=="")
		{
			$str_output = 
			$xml->employee[$i]["empname"]."-".$salary[$j];
		}
		else
		{
			$str_output = $str_output.","
			.$xml->employee[$i]["empname"]."-".$salary[$j];
		}
		
	}
}	
		
	}
	
	echo $str_output;
}

Create a function Permutation_st() which will accept a word and then return the various combinations of characters present in the word. The function should return the words in the form of an alphabetically sorted array.

Suppose we take the example of the word 'cat'. The function Permutation_st()should return an array containing the following words (in alphabetical order).

act,atc,cat,cta,tac,tca

One thing to keep in mind is that if a character is repeated in the word, the array returned should not contain duplicate elements. For example, if the word 'yyy' is sent to the function, Permutation_st("yyy") should return 'yyy' only.

function Permutation_st($str) 
{
	if (strlen($str) < 2) 
	{
		return array($str);
	}
	
	$permutations = array();
	 
	$tail = substr($str, 1);
	
	foreach (Permutation_st($tail) as $permutation) 
	{
		$length = strlen($permutation);
		for ($i = 0; $i <= $length; $i++) 
		{
			$permutations[] = substr($permutation, 0, $i) 
			. $str[0] . substr($permutation, $i);
		}
	}
	 
	return $permutations;
}

Consider a database with one table called "students" having two fields:

"id" (type: INTEGER, PRIMARY KEY)
"studentname" (type: VARCHAR(32))

Write a standard SQL query which retrieves the second lowest value of "id" from the "students" table. The value returned should be represented using the column name "id".

SELECT MIN(id) as id FROM students where id>(SELECT MIN(id) FROM students)