使用php计算排列组合的方法

前些天因为业务需要写了一段计算排列组合的代码，今天整理了一下，以备后用
复制代码 代码如下:



$CombinList = array(1 => array("Student10", "Student11"),
                    2 => array("Student20", "Student21", "Student22"),
                    3 => array("Student30"),
                    4 => array("Student40", "Student41", "Student42", "Student43"));

$CombineCount = 1;
foreach($CombinList as $Key => $Value)
{
    $CombineCount *= count($Value);
}
$RepeatTime = $CombineCount;
foreach($CombinList as $ClassNo => $StudentList)
{
    // $StudentList中的元素在拆分成组合后纵向出现的最大重复次数
    $RepeatTime = $RepeatTime / count($StudentList);
    $StartPosition = 1;
    // 开始对每个班级的学生进行循环
    foreach($StudentList as $Student)
    {
        $TempStartPosition = $StartPosition;
        $SpaceCount = $CombineCount / count($StudentList) / $RepeatTime;
        for($J = 1; $J <= $SpaceCount; $J ++)
        {
            for($I = 0; $I < $RepeatTime; $I ++)
            {
               $Result[$TempStartPosition + $I][$ClassNo] = $Student;
            }
            $TempStartPosition += $RepeatTime * count($StudentList);
        }
        $StartPosition += $RepeatTime;
    }
}

echo "

";
print_r($Result);
?>