16 lines
425 B
PHP
16 lines
425 B
PHP
<?php
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$elves = explode("\n", file_get_contents('./input.txt'));
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echo count(
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array_filter(
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$elves,
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static function($elf) {
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[$section1, $section2] = array_map(static fn($section) => explode('-', $section), explode(',', $elf));
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return count(
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array_intersect(range($section1[0], $section1[1]), range($section2[0], $section2[1]))
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) > 0;
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}
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)
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);
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