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<?php | |
function get_combinations($arrays) { | |
$result = array(array()); | |
foreach ($arrays as $property => $property_values) { | |
$tmp = array(); | |
foreach ($result as $result_item) { | |
foreach ($property_values as $property_value) { | |
$tmp[] = array_merge($result_item, array($property => $property_value)); | |
} | |
} | |
$result = $tmp; | |
} | |
return $result; | |
} | |
$combinations = get_combinations( | |
array( | |
'item1' => array('A', 'B'), | |
'item2' => array('C', 'D'), | |
'item3' => array('E', 'F'), | |
) | |
); | |
var_dump($combinations); | |
?> |
array (size=8) | |
0 => | |
array (size=3) | |
'item1' => string 'A' (length=1) | |
'item2' => string 'C' (length=1) | |
'item3' => string 'E' (length=1) | |
1 => | |
array (size=3) | |
'item1' => string 'A' (length=1) | |
'item2' => string 'C' (length=1) | |
'item3' => string 'F' (length=1) | |
2 => | |
array (size=3) | |
'item1' => string 'A' (length=1) | |
'item2' => string 'D' (length=1) | |
'item3' => string 'E' (length=1) | |
3 => | |
array (size=3) | |
'item1' => string 'A' (length=1) | |
'item2' => string 'D' (length=1) | |
'item3' => string 'F' (length=1) | |
4 => | |
array (size=3) | |
'item1' => string 'B' (length=1) | |
'item2' => string 'C' (length=1) | |
'item3' => string 'E' (length=1) | |
5 => | |
array (size=3) | |
'item1' => string 'B' (length=1) | |
'item2' => string 'C' (length=1) | |
'item3' => string 'F' (length=1) | |
6 => | |
array (size=3) | |
'item1' => string 'B' (length=1) | |
'item2' => string 'D' (length=1) | |
'item3' => string 'E' (length=1) | |
7 => | |
array (size=3) | |
'item1' => string 'B' (length=1) | |
'item2' => string 'D' (length=1) | |
'item3' => string 'F' (length=1) |
function get_combinations($arrays) {
$arrays = array_filter($arrays); //for empty index case
$result = array(array());
foreach ($arrays as $property => $property_values) {
$tmp = array();
foreach ($result as $result_item) {
foreach ($property_values as $property_value) {
$tmp[] = array_merge($result_item, array($property => $property_value));
}
}
$result = $tmp;
}
return $result;
}
Thanks! Very helpful!
Saved big hours
Many thanks!
Many many thanks!
You saved me so much time!
thanx. it's very helpful
Thanks, it helped me as well. At first I didn't understand why it does exactly what I want, even covering the case of one the arrays being empty, but doing a step by step execution clarified things. Nice job!
Thanks...saved my day
The solution works but it's extremely expansive in term time complexity, it will take O(n^) where ^ = number of arrays + 1.
I suggest this solution that is written in Java and accept any Type, put all your arrays inside one array and execute your task
public static <T> void getNumberOfOptions(List<List<T>> arr) {
// Number of arrays
int n = arr.size();
// To keep track of next element in
// each of the n arrays
int []indices = new int[n];
// Initialize with first element's index
for(int i = 0; i < n; i++)
indices[i] = 0;
while (true)
{
// Print current combination
for(int i = 0; i < n; i++) {
System.out.print(
arr.get(i).get(indices[i]) + " ");
}
System.out.println();
// Find the rightmost array that has more
// elements left after the current element
// in that array
int next = n - 1;
while (next >= 0 &&
(indices[next] + 1 >=
arr.get(next).size()))
next--;
// No such array is found so no more
// combinations left
if (next < 0)
break;
// If found move to next element in that
// array
indices[next]++;
// For all arrays to the right of this
// array current index again points to
// first element
for(int i = next + 1; i < n; i++)
indices[i] = 0;
}
}
thank you
Thanks!
Thanks, You save my time
Here's a PHP version of dernoun's Java solution.
function getNumberOfOptions(array $arr): void {
$n = count($arr);
$indices = array_fill(0, $n, 0);
while(true) {
// grab current combination for the indices.
for($i = 0; $i < $n; $i++) {
echo $arr[$i][$indices[$i]] . ' ';
}
echo "\n";
// Find the rightmost array that has more
// elements left after the current element
// in that array
$next = $n - 1;
while($next >= 0 &&
($indices[$next] + 1 >=
count($arr[$next]))
) {
$next--;
}
// No such array is found so no more
// combinations left
if ($next < 0)
break;
// If found move to next element in that
// array
$indices[$next]++;
// For all arrays to the right of this
// array current index again points to
// first element
for($i = $next + 1; $i < $n; $i++) {
$indices[$i] = 0;
}
}
}
Or if we change the function to instead return the array of combinations rather than print them, it would look like this:
function get_combinations(array $arrays): array {
$n = count($arrays);
$indices = array_fill(0, $n, 0);
$combinations = [];
while(true) {
// grab current combination for the indices.
$combination = [];
for($i = 0; $i < $n; $i++) {
$combination[] = $arrays[$i][$indices[$i]];
}
$combinations[] = $combination;
// Find the rightmost array that has more
// elements left after the current element
// in that array
$next = $n - 1;
while($next >= 0 &&
($indices[$next] + 1 >=
count($arrays[$next]))
) {
$next--;
}
// No such array is found so no more
// combinations left
if ($next < 0)
break;
// If found move to next element in that
// array
$indices[$next]++;
// For all arrays to the right of this
// array current index again points to
// first element
for($i = $next + 1; $i < $n; $i++) {
$indices[$i] = 0;
}
}
return $combinations;
}
Thanks! :)
very short code and helpful!Thanks