PHP 实现的字典序排列算法

<script>ec(2);</script>

感谢 bird 告诉我 $_POST[] 的用法。代码如下：

<?php <br />  if ($_POST["perdata"] == "")<br>  {<br>    $_POST["perdata"] = "1 2 3 4";<br>  }<br>  $data = chop (trim ($_POST["perdata"]));<br>  $a = explode (" ", $data);<br>  sort ($a);<br>  $data = implode (" ", $a);<br>?><br><?php <br />function nextpermu (&$c)<br>{<br>  $s = sizeof ($c);<br>  $i = $s - 1;<br>  while ($i > 0)<br>  {<br>    if ($c[$i] > $c[$i-1])<br>    {<br>      $j = $s-1;<br>      while ($c[$j]         $j--;<br>      $t = $c[$i-1];<br>      $c[$i-1] = $c[$j];<br>      $c[$j] = $t;<br>      //echo $i."-".$j."<br>";<br>      for ($j=$s-1; $i       {<br>        $t = $c[$i];<br>	$c[$i] = $c[$j];<br>	$c[$j] = $t;<br>      }<br>      return true;<br>    }<br>    $i--;<br>  }<br>  for ($i = 0, $j=$s-1; $i   {<br>    $t = $c[$i];<br>    $c[$i] = $c[$j];<br>    $c[$j] = $t;<br>  }<br>  return false;<br>}<br>?><br><br><br>  <title>排列－字典法</title><br><br><br>  

当前元素： echo $data; ?>

$num = 1;
do
{
?>




$num ;
}
while (nextpermu ($a));
?>

序号	排列
echo $num; ?>	echo implode (" ", $a); ?>