29 lines
645 B
PHP
29 lines
645 B
PHP
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#!/usr/bin/env php
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<?php declare(strict_types=1);
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$inputStr = file_get_contents('input.txt');
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$input = str_split($inputStr);
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$actions = array_map(fn (string $item): int => $item === '(' ? 1 : -1, $input);
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echo "Part 1: final floor:";
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echo array_reduce($actions, fn (int $a, int $b): int => $a + $b, 0) . "\n";
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function find_sum_index(array $actions, int $target = -1): int
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{
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$current = 0;
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foreach ($actions as $idx => $val)
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{
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$current += $val;
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if ($current === $target)
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{
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return $idx + 1;
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}
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}
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}
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echo "Part 2: first step in basement:";
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echo find_sum_index($actions, -1) . "\n";
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