automatische reeks | Pagina 2

<?php
// naar 26-cijferig stelsel
function to26($chars) {
  $number_array = array();

  $chars = strrev($chars);
  for($i=0; $i < strlen($chars); $i++) {
    $number_array[$i] = ord(strtolower($chars{$i})) - 97; // a=0, b=1 etc
  }
  return $number_array;
}

// 26 cijferig -> decimaal
function todec($number_array) {
  $return = 0;
  for($i=0; $i < sizeof($number_array); $i++) {
    $return += $number_array[$i] * pow(26, $i);
  }
  return $return;
}

// decimaal -> 26 cijferig
function decto26($number, $length) {
  $number_array = array();
  for($i = $length-1; $i > -1; $i--) {
    $i_aantal = (int) floor($number/pow(26, $i));
    $number_array[$i] = $i_aantal;
    $number = $number - ($i_aantal * pow(26, $i));
  }
  ksort($number_array);
  return $number_array;
}

function printnumberarray($arr) {
  $ret = "";
  for($i=sizeof($arr)-1; $i > -1; $i--) {
    $ret .= chr($arr[$i]+97);
  }
  return $ret;
}

function dumparray($arr) {
  echo "<pre>";
  print_r($arr);
  echo "</pre>";
}

$test = "abc";
echo "test: ".$test."<br />";
$test26 = to26($test);
dumparray($test26);

$testnr = todec($test26);
echo "decimaal: ".$testnr."<br />";

$test26 = decto26($testnr, 3);
echo "terug: ";
dumparray($test26);

echo "test: ".printnumberarray($test26)."<br />";

echo "start: ".todec(to26("ghi"))."<br />";
echo "eind:  ".todec(to26("zzz"))."<br />";

$start = todec(to26("ghi"));
$eind = todec(to26("zzz"));

echo "<pre>";
for($i=$start; $i <= $eind; $i++) {
  echo printnumberarray(decto26($i, 3))."\n";
}
echo "</pre>";
?>

<?php
// naar 26-cijferig stelsel
function to26($chars) {
  $number_array = array();
 
  $chars = strrev($chars);
  for($i=0; $i < strlen($chars); $i++) {
    $number_array[$i] = ord(strtolower($chars{$i})) - 97; // a=0, b=1 etc
  }
  return $number_array;
}
 
// 26 cijferig -> decimaal
function todec($number_array) {
  $return = 0;
  for($i=0; $i < sizeof($number_array); $i++) {
    $return += $number_array[$i] * pow(26, $i);
  }
  return $return;
}
 
// decimaal -> 26 cijferig
function decto26($number, $length) {
  $number_array = array();
  for($i = $length-1; $i > -1; $i--) {
    $i_aantal = (int) floor($number/pow(26, $i));
    $number_array[$i] = $i_aantal;
    $number = $number - ($i_aantal * pow(26, $i));
  }
  ksort($number_array);
  return $number_array;
}
 
function printnumberarray($arr) {
  $ret = "";
  for($i=sizeof($arr)-1; $i > -1; $i--) {
    $ret .= chr($arr[$i]+97);
  }
  return $ret;
}
 
function dumparray($arr) {
  echo "<pre>";
  print_r($arr);
  echo "</pre>";
}
 
$test = "abc";
echo "test: ".$test."<br />";
$test26 = to26($test);
dumparray($test26);
 
$testnr = todec($test26);
echo "decimaal: ".$testnr."<br />";
 
$test26 = decto26($testnr, 3);
echo "terug: ";
dumparray($test26);
 
echo "test: ".printnumberarray($test26)."<br />";
 
echo "start: ".todec(to26("ghi"))."<br />";
echo "eind:  ".todec(to26("zzz"))."<br />";
 
$start = todec(to26("ghi"));
$eind = todec(to26("zzz"));
 
echo "<pre>";
for($i=$start; $i <= $eind; $i++) {
  echo printnumberarray(decto26($i, 3))."\n";
}
echo "</pre>";
?>