数组合并及统计新组数的元素个数
$oldArr = array(array('a','b','c','d'),array('a','b'));//组成一个新的二维数组,样式如下$newArray = array(array('a','a'),array('a','b'),array('b','a'),array('b','b'),.......array('d','b'));//$oldArry子子元素的个数未知,就是需要组成一个新的二维数组,并去掉元素相同的数组如:array('a','a'),array('b','b');
想了一个晚上,也不知道怎么弄,还有升级的
如果$oldArr的元素是三个的话,那么$newarray子子元素的数量也是三个:
$oldArr = array(array('a','b','c','d'),array('a','b'),array('e','f','g'));$newArray = array(array('a','a','e'),array('a','a','f'),array('a','a','f'),array('a','b','e'),.......array('d','b','g'));//同样要去掉元素相同的数组,只能留下三个不同的元素,如:array('a','a','e’),array('a','a','f')
回复讨论(解决方案)
你的基础算法是求笛卡尔积
笛卡尔(Descartes)乘积又叫直积。设A、B是任意两个集合,在集合A中任意取一个元素x,在集合B中任意取一个元素y,组成一个有序对(x,y),把这样的有序对作为新的元素,他们的全体组成的集合称为集合A和集合B的直积,记为A×B,即A×B={(x,y)|x∈A且y∈B}。
有关笛卡尔积的讨论,在精华区收录了不少,你可以去看看
鉴于你有对结果数组过滤的要求,所以取一种并用回调函数实现过滤
$oldArr = array(array('a','b','c','d'),array('a','b'));//$oldArr = array(array('a','b','c','d'),array('a','b'),array('e','f','g'));print_r(Descartes($oldArr, 'foo'));function foo($a) { return count($a) == count(array_count_values($a));}function Descartes($d, $func='') { $r = array_pop($d); while($d) { $t = array(); $s = array_pop($d); if(! is_array($s)) $s = array($s); foreach($s as $x) { foreach($r as $y) { $m = array_merge(array($x), is_array($y) ? $y : array($y)); if($func && $func($m)) $t[] = $m; } } $r = $t; } return $r;}
Array( [0] => Array ( [0] => a [1] => b ) [1] => Array ( [0] => b [1] => a ) [2] => Array ( [0] => c [1] => a ) [3] => Array ( [0] => c [1] => b ) [4] => Array ( [0] => d [1] => a ) [5] => Array ( [0] => d [1] => b ))
版本牛x,对的,就是求笛卡尔积

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