PHP基于自定义函数生成笛卡尔积的方法示例
本文实例讲述了PHP基于自定义函数生成笛卡尔积的方法。分享给大家供大家参考，具体如下：
<?php
$color = array('red', 'green');
$size = array(39, 40, 41);
$local = array('beijing', 'shanghai');
echo "<pre>";
print_r(combineDika($color, $size, $local));
/**
* 所有数组的笛卡尔积
*
* @param unknown_type $data
*/
function combineDika() {
$data = func_get_args();
$cnt = count($data);
$result = array();
foreach($data[0] as $item) {
$result[] = array($item);
}
for($i = 1; $i < $cnt; $i++) {
$result = combineArray($result,$data[$i]);
}
return $result;
}
/**
* 两个数组的笛卡尔积
*
* @param unknown_type $arr1
* @param unknown_type $arr2
*/
function combineArray($arr1,$arr2) {
$result = array();
foreach ($arr1 as $item1) {
foreach ($arr2 as $item2) {
$temp = $item1;
$temp[] = $item2;
$result[] = $temp;
}
}
return $result;
}
?>
运行结果：
Array
(
[0] => Array
(
[0] => red
[1] => 39
[2] => beijing
)
[1] => Array
(
[0] => red
[1] => 39
[2] => shanghai
)
[2] => Array
(
[0] => red
[1] => 40
[2] => beijing
)
[3] => Array
(
[0] => red
[1] => 40
[2] => shanghai
)
[4] => Array
(
[0] => red
[1] => 41
[2] => beijing
)
[5] => Array
(
[0] => red
[1] => 41
[2] => shanghai
)
[6] => Array
(
[0] => green
[1] => 39
[2] => beijing
)
[7] => Array
(
[0] => green
[1] => 39
[2] => shanghai
)
[8] => Array
(
[0] => green
[1] => 40
[2] => beijing
)
[9] => Array
(
[0] => green
[1] => 40
[2] => shanghai
)
[10] => Array
(
[0] => green
[1] => 41
[2] => beijing
)
[11] => Array
(
[0] => green
[1] => 41
[2] => shanghai
)
)
PS：这里再为大家推荐几款计算工具供大家进一步参考借鉴：
在线一元函数（方程）求解计算工具：
http://tools.jb51.net/jisuanqi/equ_jisuanqi
科学计算器在线使用_高级计算器在线计算：
http://tools.jb51.net/jisuanqi/jsqkexue
在线计算器_标准计算器：
http://tools.jb51.net/jisuanqi/jsq
更多关于PHP相关内容感兴趣的读者可查看本站专题：《PHP数学运算技巧总结》、《PHP运算与运算符用法总结》、《php字符串(string)用法总结》、《PHP数组(Array)操作技巧大全》、《PHP数据结构与算法教程》、《php程序设计算法总结》及《php正则表达式用法总结》
希望本文所述对大家PHP程序设计有所帮助。