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<?php |
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namespace DaanMooij\AdventOfCode\Year2015\Day1; |
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use DaanMooij\AdventOfCode\Day; |
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use Exception; |
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class Day1 implements Day |
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{ |
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private const FLOOR_UP = '('; |
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private const FLOOR_DOWN = ')'; |
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private const STARTING_FLOOR = 0; |
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/** |
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* @var array<string> |
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*/ |
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private array $directions = []; |
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/** |
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* @return void |
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*/ |
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public function loadInput(): void |
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{ |
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$filepath = __DIR__ . "/input.txt"; |
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$file = file_get_contents($filepath); |
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if (!is_string($file)) { |
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throw new Exception("Could not open input file: {$filepath}"); |
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} |
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$this->directions = str_split($file) ?? []; |
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} |
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/** |
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* @return void |
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*/ |
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public function solve(): void |
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{ |
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printf("The resulting floor is: %s\n", $this->calculateFloor(self::STARTING_FLOOR)); |
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printf( |
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"The first direction position that causus Santa to go in the basement is: %s\n", |
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$this->calculateFirstBasementDirectionPosition(self::STARTING_FLOOR) |
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); |
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} |
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/** |
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* @param int $floor |
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* @return int |
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*/ |
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public function calculateFloor(int $floor = self::STARTING_FLOOR): int |
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{ |
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foreach ($this->directions as $direction) { |
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if ($direction === self::FLOOR_UP) { |
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$floor++; |
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} elseif ($direction === self::FLOOR_DOWN) { |
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$floor--; |
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} |
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} |
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return $floor; |
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} |
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/** |
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* @param int $floor |
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* @return int |
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*/ |
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public function calculateFirstBasementDirectionPosition(int $floor = self::STARTING_FLOOR): int |
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{ |
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if ($floor < 0) { |
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return 0; |
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} |
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$basementPostion = 1; |
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$inBasement = false; |
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while (!$inBasement) { |
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foreach ($this->directions as $position => $direction) { |
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if ($direction === self::FLOOR_UP) { |
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$floor++; |
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} elseif ($direction === self::FLOOR_DOWN) { |
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if ($floor === 0) { |
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$basementPostion = $position + 1; |
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$inBasement = true; |
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break; |
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} |
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$floor--; |
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} |
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$basementPostion = $position + 1; |
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} |
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} |
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return $basementPostion; |
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} |
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/** |
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* @param array<string> $directions |
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* @return void |
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*/ |
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public function setDirections(array $directions): void |
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{ |
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$this->directions = $directions; |
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} |
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/** |
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* @return array<string> |
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*/ |
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public function getDirections(): array |
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{ |
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return $this->directions; |
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} |
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} |
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daanmooij /
advent-of-code-php
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