Group pairs in array - php

Question

I'm trying to group airlines with relations into single chains.
Array
(
[0] => Array
(
[0] => Aeroflot
[1] => S7
[2] => Transaero
)
[1] => Array
(
[0] => Alitalia
[1] => Lufthansa
)
[2] => Array
(
[0] => Transaero
[1] => United
)
[3] => Array
(
[0] => United
[1] => Alitalia
)
[4] => Array
(
[0] => Volotea
[1] => Iberia
)
[5] => Array
(
[0] => Transaero
[1] => Aeroflot
)
)
From that array I need to find connections between elements and combine it to groups. Expected results:
Array
(
[0] => Array
(
[0] => Aeroflot
[1] => S7
[2] => Transaero
[3] => United
[4] => Alitalia
[5] => Lufthansa
)
[1] => Array
(
[0] => Volotea
[1] => Iberia
)
)
Can anyone help with that? I've tried a dozen of ways but still get no success.
The most closest way I've tried which works but not in all cases:
function array_searchRecursive($needle,$haystack) {
foreach($haystack as $key=>$value) {
$current_key=$key;
if($needle===$value OR (is_array($value) && array_searchRecursive($needle,$value) !== false)) {
return $current_key;
}
}
return false;
}
foreach ($newarr as $key => $airlines)
{
foreach ($airlines as $lastkey => $airline)
{
$index = array_searchRecursive($airline,$newarr);
echo $airline.$index."\n";
if ($index !== false)
{
$newarr[$index] = array_merge($newarr[$index],$airlines);
$lastarr[] = $index;
}
}
}
But it doesn't match all values in array.

Answer 1

Recursive function will help you. You are welcome )
$arr = array(
array('Aeroflot','S7','Transaero'),
array('Alitalia','Lufthansa'),
array('Transaero','United'),
array('United','Alitalia'),
array('Volotea','Iberia'),
array('Transaero','Aeroflot')
);
function getConnections($arr,$curr_line_n=0,$num=0) {
for($i=0;$i<count($arr[$curr_line_n]);$i++) {
$cur_air_name = $arr[$curr_line_n][$i];
for($k=$curr_line_n+1; $k<count($arr); $k++) {
for($l=0;$l<count($arr[$k]);$l++) {
if ($arr[$k][$l]==$cur_air_name) {
$arr[$curr_line_n] = array_values(array_unique(array_merge($arr[$curr_line_n],$arr[$k])));
array_splice($arr,$k,1);
$num++;
$arr = getConnections($arr,$curr_line_n,$num);
}
}
}
}
$num++;
$curr_line_n++;
if ($curr_line_n!=count($arr)) {
$arr = getConnections($arr,$curr_line_n,$num);
}
return $arr;
}
print_r(getConnections($arr));

Answer 2

As per your example you are just grouping sub arrays by taking first sub array as reference. for example if you have any elements common in first sub array and in subsequent sub arrays then you combine them into one sub array.
<?php
$arr = array(
array('a', 'b', 'c', 'd'),
array('d', 't'),
array('t', 'f'),
array('k', 'o'),
array('p', 'z')
);
$arr_implode = array();
foreach ($arr as $key => $value) {
if (is_array($value)) {
$arr_implode[$key] = implode('', $value);
} else {
$arr_implode[$key] = $value;
}
}
$arr_key = array();
$result = array();
$count = count($arr_implode);
$tempj = 0;
for ($i = 0; $i <= $count; $i++) {
$flag = FALSE;
for ($j = ($i + 1); $j < $count; $j++) {
similar_text($arr_implode[$i], $arr_implode[$j], $percent);
if ($percent > 0) {
$result[] = array_merge($arr[$i],$arr[$j]);
break;
} else {
$result[] = $arr[$j];
break;
}
}
}
foreach($result as $key => $val){
$result[$key] = array_unique($val);
}
echo "<pre>";
print_r($result);
echo "</pre>";
?>
Try this code.

Answer 3

$arr = [
['Aeroflot', 'S7', 'Transaero'],
['Alitalia', 'Lufthansa'],
['Transaero', 'United'],
['United', 'Alitalia'],
['Volotea', 'Iberia'],
['Transaero', 'Aeroflot']
];
$hash = [];
$result = [];
foreach($arr as $set){
foreach($set as $el){
if(!$hash[$el]) $hash[$el] = [] ;
$hash[$el] = array_merge($hash[$el], $set);
}
}
function merge_connections(&$h, $key){
if(!$h[$key]) return [];
$data = [$key];
$rels = $h[$key];
unset($h[$key]);
foreach($rels as $rel){
if($rel==$key) continue;
$data = array_merge($data, merge_connections($h, $rel));
}
return $data;
}
foreach(array_keys($hash) as $company){
if(!$hash[$company]) continue;
array_push($result, merge_connections($hash, $company));
}
print_r($result);