Move solutions out of the source itself

data/Y21/day4/Day4.php

@@ -0,0 +1,191 @@
+<?php
+
+namespace trizz\AdventOfCode\Y21;
+
+use trizz\AdventOfCode\Solution;
+
+final class Day4 extends Solution
+{
+    public static null|int|string $part1ExampleResult = 4512;
+
+    public static null|int|string $part1Result = 60368;
+
+    public static null|int|string $part2ExampleResult = 1924;
+
+    public static null|int|string $part2Result = 17435;
+
+    #[\Override]
+    public function part1(array $data): int|string
+    {
+        return $this->playBingo($data, firstWins: true);
+    }
+
+    #[\Override]
+    public function part2(array $data): int|string
+    {
+        return $this->playBingo($data, firstWins: false);
+    }
+
+    /**
+     * @param int[] $winningCard
+     *
+     * @psalm-param array<int, array<array-key, bool|int>|string> $winningCard
+     */
+    private function calculateScore(array $winningCard, int $number): int
+    {
+        $return = [];
+        array_walk_recursive($winningCard, static function (bool $value, int $key) use (&$return): void {
+            $return[$key] = $value;
+        });
+        $unusedNumbers = array_keys(array_filter($return, static fn (bool $value): bool => !$value));
+
+        return (int) array_sum($unusedNumbers) * $number;
+    }
+
+    /**
+     * @param non-empty-string $separator
+     *
+     * @return int[]
+     *
+     * @psalm-return array<int, int>
+     */
+    private function explodeNumbers(string $numberList, string $separator): array
+    {
+        return array_map(
+            static fn ($value): int => (int) $value,
+            array_filter(
+                explode($separator, $numberList),
+                static fn (string $value): bool => $value !== ''
+            )
+        );
+    }
+
+    /**
+     * @param string[] $data
+     */
+    private function playBingo(array $data, bool $firstWins = true): int|string
+    {
+        $numbers = $this->explodeNumbers(array_shift($data) ?? '', ',');
+        $cards = $this->setupCards($data);
+        $finishedCards = [];
+
+        // Call the numbers.
+        foreach ($numbers as $number) {
+            /**
+             * @var int   $cardIndex
+             * @var int[] $cardRows
+             */
+            foreach ($cards as $cardIndex => $cardRows) {
+                if (isset($finishedCards[$cardIndex])) {
+                    continue;
+                }
+
+                /**
+                 * @var int   $cardRowIndex
+                 * @var int[] $cardRow
+                 */
+                foreach ($cardRows as $cardRowIndex => $cardRow) {
+                    if (isset($cardRow[$number])) {
+                        $cards[$cardIndex][$cardRowIndex][$number] = true;
+                    }
+                }
+            }
+
+            $winningCards = $this->checkCards($cards, $finishedCards);
+            if ($winningCards === []) {
+                continue;
+            }
+
+            foreach ($winningCards as $winningCard) {
+                $lastWinningCard = $cards[$winningCard];
+                $lastWinNumber = $number;
+                $finishedCards[$winningCard] = true;
+
+                if ($firstWins) {
+                    return $this->calculateScore($lastWinningCard, $number);
+                }
+            }
+        }
+
+        if (isset($lastWinningCard, $lastWinNumber)) {
+            return $this->calculateScore($lastWinningCard, $lastWinNumber);
+        }
+
+        return 'Computer says no...';
+    }
+
+    /**
+     * @param string[] $data
+     *
+     * @return ((false|int)[]|string)[][]
+     *
+     * @psalm-return array<int, array<int, array<false|int>|string>>
+     */
+    private function setupCards(array $data): array
+    {
+        $cards = array_chunk($data, 5);
+        foreach ($cards as $card => $rows) {
+            $cards[$card] = array_map(fn ($value): array => $this->explodeNumbers($value, ' '), $rows);
+
+            foreach ($cards[$card] as $row => $number) {
+                $cards[$card][$row] = array_fill_keys(array_values($number), false);
+            }
+        }
+
+        return $cards;
+    }
+
+    /**
+     * @return int[]
+     *
+     * @psalm-return list<int>
+     */
+    private function checkCards(array $cards, array $finishedCards): array
+    {
+        $winningCards = [];
+
+        // Check rows
+        /**
+         * @var int   $cardIndex
+         * @var int[] $rows
+         */
+        foreach ($cards as $cardIndex => $rows) {
+            if (isset($finishedCards[$cardIndex])) {
+                continue;
+            }
+
+            /** @var int[] $row */
+            foreach ($rows as $row) {
+                if ($this->arrayHasSingleValue($row, true)) {
+                    $winningCards[] = $cardIndex;
+                }
+            }
+
+            // Get the vertical numbers.
+            $colValues = [];
+            for ($rowIndex = 0; $rowIndex < 5; ++$rowIndex) {
+                for ($colIndex = 0; $colIndex < 5; ++$colIndex) {
+                    if (!isset($colValues[$colIndex])) {
+                        $colValues[$colIndex] = [];
+                    }
+
+                    $colValues[$colIndex] += array_slice((array) $rows[$rowIndex], $colIndex, 1, preserve_keys: true);
+                }
+            }
+
+            // See if there's a bingo on the vertical numbers.
+            foreach ($colValues as $colIndex => $colValue) {
+                if ($this->arrayHasSingleValue($colValue, true)) {
+                    $winningCards[] = $cardIndex;
+                }
+            }
+        }
+
+        return $winningCards;
+    }
+
+    private function arrayHasSingleValue(array $array, bool $value): bool
+    {
+        return count(array_unique($array)) === 1 && end($array) === $value;
+    }
+}