23 lines
538 B
PHP
23 lines
538 B
PHP
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<?php
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$instructions = explode("\n", file_get_contents('input.txt'));
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$position = 0;
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$depth = 0;
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foreach ($instructions as $instruction) {
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[$movement, $value] = explode(' ', $instruction);
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switch ($movement) {
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case 'forward':
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$position += $value;
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break;
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case 'up':
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$depth -= $value;
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break;
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case 'down':
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$depth += $value;
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break;
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}
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}
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echo sprintf('horizontal position %s × depth %s = %s', $position, $depth, $position * $depth);
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