本文用PHP要解决的数学问题是算出C(a,1) * C(b, 1) * ... * C(n, 1)的组合情况，其中C(n, 1)代表从n个元素里任意取一个元素
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
代码如下:
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)
{ //unity3d http://www.unitymanual.com
// $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);
?>
