Created
September 9, 2014 10:32
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<?php | |
// dnepr -> ujgorod -> poltava -> kharkov -> kiev => odessa -> lvov -> doceck | |
$tickets = [ | |
['start' => 'kiev', 'finish' => 'odessa'], | |
['start' => 'dnepr', 'finish' => 'ujgorod'], | |
['start' => 'odessa', 'finish' => 'lvov'], | |
['start' => 'kharkov', 'finish' => 'kiev'], | |
['start' => 'poltava', 'finish' => 'kharkov'], | |
['start' => 'ujgorod', 'finish' => 'poltava'], | |
['start' => 'lvov', 'finish' => 'doneck'], | |
['start' => 'lvov1', 'finish' => 'doneck'], | |
['start' => 'lvov', 'finish' => 'doneck1'] | |
]; | |
function getStacks($list) { | |
$stacks = []; | |
foreach ($list as $item) { | |
$stacked = false; | |
// crunch | |
if (!isset($item['items'])) { | |
$item['items'] = [$item]; | |
} | |
foreach ($stacks as &$stack) { | |
if ($stack['start'] == $item['finish'] && !$stacked) { | |
$stack['items'] = array_merge($item['items'], $stack['items']); // unshift | |
$stack['start'] = $item['start']; | |
$stacked = true; | |
} | |
if ($stack['finish'] == $item['start'] && !$stacked) { | |
$stack['items'] = array_merge($stack['items'], $item['items']); // push | |
$stack['finish'] = $item['finish']; | |
$stacked = true; | |
} | |
} | |
if ($stacked == false ) { | |
$stacks[] = $item; | |
} | |
} | |
return $stacks; | |
} | |
$iterations = 0; | |
$initialTicketsSize = sizeof($tickets); | |
do { | |
$tickets = getStacks($tickets); | |
$iterations++; | |
} while (sizeof($tickets) != 1 && $iterations <= $initialTicketsSize); | |
var_dump($tickets); | |
var_dump($iterations); |
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