好的，我知道了：
<?php
require_once('query.lib.php');
$db=new database(DB_TYPE,DB_HOST,DB_USER,DB_PASS,DB_MISC);
$qry=new query('set names utf8',$db);
//Base query, this filters out names that are in just one family
$sql='select name, cast(group_concat(family order by family) as char) as famlist, count(*) as num from people group by name having num>0 order by num desc';
$qry=new query($sql,$db);
//$qry->result is something like
/*
Array
(
[name] => Array
(
[0] => cathy
[1] => george
[2] => jack
[3] => john
[4] => jane
[5] => winston
[6] => peter
)
[famlist] => Array
(
[0] => 2,4,5,6,8
[1] => 2,3,4,5,8
[2] => 1,3,5,7,8
[3] => 1,2,3,6,7
[4] => 2,4,7,8
[5] => 1,2,6,8
[6] => 1,3,6
)
[num] => Array
(
[0] => 5
[1] => 5
[2] => 5
[3] => 5
[4] => 4
[5] => 4
[6] => 3
)
)
$qry->rows=7
*/
//Initialize
$names=$qry->result['name'];
$rows=$qry->rows;
$lists=array();
for ($i=0;$i<$rows;$i++) $lists[$i]=explode(',',$qry->result['famlist'][$i]);
//Walk the list and populate pairs - this filters out pairs, that are specific to only one family
$tuples=array();
for ($i=0;$i<$rows;$i++) {
for ($j=$i+1;$j<$rows;$j++) {
$isec=array_intersect($lists[$i],$lists[$j]);
if (sizeof($isec)>1) {
//Every tuple consists of the name-list, the family list, the length and the latest used name
$tuples[]=array($names[$i].'/'.$names[$j],$isec,2,$j);
}
}
}
//Now walk the tuples again rolling forward, until there is nothing left to do
//We do not use a for loop just for style
$i=0;
while ($i<sizeof($tuples)) {
$tuple=$tuples[$i];
//Try to combine this tuple with all later names
for ($j=$tuple[3]+1;$j<$rows;$j++) {
$isec=array_intersect($tuple[1],$lists[$j]);
if (sizeof($isec)>0) $tuples[]=array($tuple[0].'/'.$names[$j],$isec,$tuple[2]+1,$j);
}
$i++;
}
//We have all the tuples, now we just need to extract the info and prepare to sort - some dirty trick here!
$final=array();
while (sizeof($tuples)>0) {
$tuple=array_pop($tuples);
//name list is in $tuple[0]
$list=$tuple[0];
//count is sizeof($tuple[1])
$count=sizeof($tuple[1]);
//length is in $tuple[2]
$final[]=$tuple[2]*$count."\t$count\t$list";
}
//Sorting and output is all that is left
rsort($final);
print_r($final);
?>
很抱歉，我刚刚意识到我使用了一个无法在此处获取的查询库，但从评论中您将能够轻松地创建数组，如“初始化”部分中所示。
基本上我所做的是从我保留当前名称列表中所有名称所属的家庭数组的对开始，然后将其与所有尚未尝试过的名称相交。