Split array into combinations according to number of values - php

Question

What is the best way to split the following array to different combinations according to number of values?
[0] => 1
[1] => 5
[2] => 4
[3] => 1
[4] => Array
(
[0] => 1
[1] => 9
)
To
[0] => 1
[1] => 5
[2] => 4
[3] => 1
[4] => 1
AND
[0] => 1
[1] => 5
[2] => 4
[3] => 1
[4] => 9

Answer 1

function getCombinations($arr){
$ret = array();
$subs = array();
// extract sub arrays
$n = count($arr);
for($i=0;$i<$n;$i++){
if(is_array($arr[$i])){
$subs[] = array('target'=>$i, 'values'=>$arr[$i], 'size'=>count($arr[$i]), 'counter'=>0);
$arr[$i] = null;
}
}
$subs_n = count($subs);
if($subs_n==0) // no subarrays found, return input
return $arr;
$finished = false;
while(!$finished){
$combination = $arr; // this will copy the existing array
for($i=0;$i<$subs_n;$i++){
$combination[$subs[$i]['target']] = $subs[$i]['values'][$subs[$i]['counter']]; // write current combination into designated index
}
$ret[] = $combination; // add combination to output
$carry = true;
$i = 0;
while($carry){
$subs[$i]['counter']++; //next combination
if($subs[$i]['counter']>=$subs[$i]['size']){ // if end of combination, increment next level
$carry = true;
$subs[$i]['counter'] = 0;
}else{
$carry = false;
}
$i++;
if($i>=$subs_n && $carry){ // if last combination reached, all done
$finished = true;
$carry = false;
}
}
}
return $ret;
}

Answer 2

I'd go with something like this:
<?php
$arr = [
0 => 1,
1 => 5,
2 => 4,
3 => 1,
4 => [
0 => 1,
1 => 9,
]
];
$arr = [
0 => null,
1 => $arr,
];
function split_array($a) {
$ended = true;
$new_line = [];
$rem_line = [];
$last_line = array_pop($a);
foreach ($last_line as $k=>$v){
if ( is_array( $v ) ) {
$new_v = array_shift($v);
if ( count($v) > 0 ) {
$rem_v = $v;
$ended = false;
} else {
$rem_v = $new_v;
}
} else {
$new_v = $v;
$rem_v = $v;
}
$new_line[] = $new_v;
$rem_line[] = $rem_v;
}
$a[] = $new_line;
if ( ! $ended ) {
echo 'not ended';
$a[] = $rem_line;
$a = split_array($a);
}
return $a;
}
array_shift($arr);
echo '<pre>';
print_r( split_array($arr) );
echo '</pre>';