Task

For each number list of 6-digit SEDOLs, calculate and append the checksum digit.



That is, given this input:

710889
B0YBKJ
406566
B0YBLH
228276
B0YBKL
557910
B0YBKR
585284
B0YBKT
B00030

Produce this output:

7108899
B0YBKJ7
4065663
B0YBLH2
2282765
B0YBKL9
5579107
B0YBKR5
5852842
B0YBKT7
B000300

Extra credit

Check each input is correctly formed, especially with respect to valid characters allowed in a SEDOL string.



Related tasks

   Luhn test
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function char2value($c) {
  assert(stripos('AEIOU', $c) === FALSE);
  return intval($c, 36);
}
 
$sedolweight = array(1,3,1,7,3,9);
 
function checksum($sedol) {
    global $sedolweight;
    $tmp = array_sum(array_map(create_function('$ch, $weight', 'return char2value($ch) * $weight;'),
                               str_split($sedol), $sedolweight)
                    );
    return strval((10 - ($tmp % 10)) % 10);
}
 
foreach (array('710889',
               'B0YBKJ',
               '406566',
               'B0YBLH',
               '228276',
               'B0YBKL',
               '557910',
               'B0YBKR',
               '585284',
               'B0YBKT') as $sedol)
    echo $sedol, checksum($sedol), "\n";