Получить все уникальные комбинации массивов, используя декартово переполнение стека продуктов
Я пытаюсь получить все возможные комбинации для неизвестного числа массивов как таковых:
Вот структура данных JSON
[
{
"department": "CIS",
"name": "Intro to CIS",
"sections": [
{
"sectionNumber": "01",
"regNum": "012345",
"days": "MWF",
"startTime": "900",
"endTime": "1030",
"labDay": "M",
"labStartTime": "1300",
"labEndTime": "1500"},
{
"sectionNumber": "02",
"regNum": "098304",
"days": "TR",
"startTime": "1300",
"endTime": "1500",
"labDay": "",
"labStartTime": "",
"labEndTime": ""}
]
},
{
"department": "MATH",
"name": "Intro to MATH",
"sections": [
{
"sectionNumber": "01",
"regNum": "012345",
"days": "MWF",
"startTime": "900",
"endTime": "1030",
"labDay": "M",
"labStartTime": "1300",
"labEndTime": "1500"},
{
"sectionNumber": "02",
"regNum": "098304",
"days": "TR",
"startTime": "1300",
"endTime": "1500",
"labDay": "",
"labStartTime": "",
"labEndTime": ""}
]
}
]
Я хотел бы, чтобы результат был следующим: Результат должен содержать весь ассоциативный массив курса, чтобы я мог получить доступ ко всем его данным (sectionNumber, regNum, days, ..etc)
Обратите внимание, я не знаю, сколько будет курсов или разделов. Кроме того, курс никогда не должен сравнивать себя.
Желаемый результат:
[
[ [CIS 01 Array],[MATH 01 Array] ],
[ [CIS 01 Array],[MATH 02 Array] ],
[ [CIS 02 Array],[MATH 01 Array] ],
[ [CIS 02 Array],[MATH 02 Array]]
]
Каждый результирующий массив должен содержать массивы (которые имеют длину, равную количеству курсов) массивов.
Я думаю, что я должен использовать декартово произведение, но я не совсем уверен, как это реализовать.
Я начал делать что-то подобное, но я знаю, что это не правильно
for($i = 0; $i < count($json_data); $i++){ //courses
for($k = 0; $k < count($json_data[$i]["sections"]); $k++){ //first sections
for($p = 1; $p < count($json_data[$i]["sections"]); $p++){ //all other courses but 1
for($h = 0; $h < count($json_data[$i]["sections"][$p]); $h++){
echo $json_data[$i]["sections"][$k]["labDay"];
}
}
}
}
Решение
Вот типовое решение для кросс-продукта (не мое, я где-то его нашел, не помню где, но в сети есть куча):
function crossProduct() {
$_ = func_get_args();
if (count($_) == 0) {
return array(array());
}
$a = array_shift($_);
$c = call_user_func_array('crossProduct', $_);
$r = array();
foreach ($a as $v) {
foreach ($c as $p) {
$r[] = array_merge(array($v), $p);
}
}
return $r;
}
Однако вам нужно будет немного предварительно обработать ваше решение:
$allDepartmentsSections = [];
foreach ($jsonArrayEntry as $entry) {
$sections = [];
foreach ($entry["section"] as $section) {
$sections[] = $section + [ "department" => $entry["department"], "name"=>$entry["name"] ];
}
$allDepartmentsSections[] = $sections;
}
Затем вы можете сделать:
call_user_func_array('crossProduct', $allDepartmentsSections);
Посмотрите, как это работает в https://eval.in/725763
Другие решения
Проверьте любой из следующих классов:
jwage / Cartesian.php
Математика / Комбинаторика / Комбинация / CartesianProduct.php
Вот мое решение:
//simplified json for answer, you could use yours
$json = '[
{
"department": "CIS",
"sections": [
{
"sectionNumber": "CIS-1"},
{
"sectionNumber": "CIS-2"}
]
},{
"department": "ENG",
"sections": [
{
"sectionNumber": "ENG-1"},
{
"sectionNumber": "ENG-2"}
]
},
{
"department": "MATH",
"sections": [
{
"sectionNumber": "MATH-1"},
{
"sectionNumber": "MATH-2"}
]
}
]';
$data = json_decode($json, true);
$cartesian = [];
//Use array map to run over all array items
array_map(function($item) use($data, &$cartesian) {
//starting from your element, search for all others "next departments"for($i = array_search($item, $data)+1, $c = count($data); $i<$c; $i++) {
//foreach "next departments" get section
foreach($data[$i]['sections'] as $section) {
//foreach sections of current department, do
foreach($item['sections'] as $item_section) {
//append to cartesian resultset
$cartesian[] = [$item_section, $section];
}
}
}
}, $data);
//create a reverse array, to get all reverse combinations.
// Ex.: We have CIS-1 -> MATH-1, now we have MATH-1 -> CIS-1
$reverse = array_map('array_reverse', $cartesian);
//merge to cartesian resultset
$cartesian = array_merge($cartesian, $reverse);
print_r(count($cartesian)); print_r($cartesian);
Выход:
24
Array
(
[0] => Array
(
[0] => Array
(
[sectionNumber] => CIS-1
)
[1] => Array
(
[sectionNumber] => ENG-1
)
)
[1] => Array
(
[0] => Array
(
[sectionNumber] => CIS-2
)
[1] => Array
(
[sectionNumber] => ENG-1
)
)
[2] => Array
(
[0] => Array
(
[sectionNumber] => CIS-1
)
[1] => Array
(
[sectionNumber] => ENG-2
)
)
[3] => Array
(
[0] => Array
(
[sectionNumber] => CIS-2
)
[1] => Array
(
[sectionNumber] => ENG-2
)
)
[4] => Array
(
[0] => Array
(
[sectionNumber] => CIS-1
)
[1] => Array
(
[sectionNumber] => MATH-1
)
)
[5] => Array
(
[0] => Array
(
[sectionNumber] => CIS-2
)
[1] => Array
(
[sectionNumber] => MATH-1
)
)
[6] => Array
(
[0] => Array
(
[sectionNumber] => CIS-1
)
[1] => Array
(
[sectionNumber] => MATH-2
)
)
[7] => Array
(
[0] => Array
(
[sectionNumber] => CIS-2
)
[1] => Array
(
[sectionNumber] => MATH-2
)
)
[8] => Array
(
[0] => Array
(
[sectionNumber] => ENG-1
)
[1] => Array
(
[sectionNumber] => MATH-1
)
)
[9] => Array
(
[0] => Array
(
[sectionNumber] => ENG-2
)
[1] => Array
(
[sectionNumber] => MATH-1
)
)
[10] => Array
(
[0] => Array
(
[sectionNumber] => ENG-1
)
[1] => Array
(
[sectionNumber] => MATH-2
)
)
[11] => Array
(
[0] => Array
(
[sectionNumber] => ENG-2
)
[1] => Array
(
[sectionNumber] => MATH-2
)
)
[12] => Array
(
[0] => Array
(
[sectionNumber] => ENG-1
)
[1] => Array
(
[sectionNumber] => CIS-1
)
)
[13] => Array
(
[0] => Array
(
[sectionNumber] => ENG-1
)
[1] => Array
(
[sectionNumber] => CIS-2
)
)
[14] => Array
(
[0] => Array
(
[sectionNumber] => ENG-2
)
[1] => Array
(
[sectionNumber] => CIS-1
)
)
[15] => Array
(
[0] => Array
(
[sectionNumber] => ENG-2
)
[1] => Array
(
[sectionNumber] => CIS-2
)
)
[16] => Array
(
[0] => Array
(
[sectionNumber] => MATH-1
)
[1] => Array
(
[sectionNumber] => CIS-1
)
)
[17] => Array
(
[0] => Array
(
[sectionNumber] => MATH-1
)
[1] => Array
(
[sectionNumber] => CIS-2
)
)
[18] => Array
(
[0] => Array
(
[sectionNumber] => MATH-2
)
[1] => Array
(
[sectionNumber] => CIS-1
)
)
[19] => Array
(
[0] => Array
(
[sectionNumber] => MATH-2
)
[1] => Array
(
[sectionNumber] => CIS-2
)
)
[20] => Array
(
[0] => Array
(
[sectionNumber] => MATH-1
)
[1] => Array
(
[sectionNumber] => ENG-1
)
)
[21] => Array
(
[0] => Array
(
[sectionNumber] => MATH-1
)
[1] => Array
(
[sectionNumber] => ENG-2
)
)
[22] => Array
(
[0] => Array
(
[sectionNumber] => MATH-2
)
[1] => Array
(
[sectionNumber] => ENG-1
)
)
[23] => Array
(
[0] => Array
(
[sectionNumber] => MATH-2
)
[1] => Array
(
[sectionNumber] => ENG-2
)
)
)