21 lines
514 B
PHP
21 lines
514 B
PHP
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<?php
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$groups = explode("\n\n", file_get_contents('input.txt'));
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$yesses = 0;
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foreach ($groups as $group) {
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$persons = explode("\n", $group);
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if (count($persons) === 1) {
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$yesses += strlen(current(array_unique($persons)));
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} else {
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$persons_letters = array_map(static function($person) {
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return array_unique(str_split($person));
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}, $persons);
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$intersect = array_intersect(...$persons_letters);
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$yesses += count($intersect);
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}
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}
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echo $yesses;
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