Dominoes Length of Longest Chain Solution (PHP)

Dominoes.php

<?php

declare(strict_types=1);

final class Dominoes
{
    public function maxLength(string $string): int
    {
        /** @var Tile[] $tiles */
        $tiles = \array_map(function ($tile) {
            return Tile::fromString($tile);
        }, \explode(',', $string));

        $count = \count($tiles);
        if ($count < 2) {
            return $count;
        }

        $maxLength = 1;
        $currentLength = 1;

        $tile = \array_shift($tiles);

        foreach ($tiles as $nextTile) {
            if ($tile->right() === $nextTile->left()) {
                ++$currentLength;

                $maxLength = \max(
                    $maxLength,
                    $currentLength
                );
            } else {
                $currentLength = 1;
            }

            $tile = $nextTile;
        }

        return $maxLength;
    }
}

Tile.php

<?php

declare(strict_types=1);

namespace Localheinz\Toptal;

final class Tile
{
    /**
     * @var string
     */
    private $left;

    /**
     * @var string
     */
    private $right;

    public function __construct(string $left, string $right)
    {
        $this->left = $left;
        $this->right = $right;
    }

    public function left(): string
    {
        return $this->left;
    }

    public function right(): string
    {
        return $this->right;
    }

    public static function fromString(string $tile): self
    {
        $sides = \explode('-', $tile);

        return new self(
            $sides[0],
            $sides[1]
        );
    }
}