CartesianProduct.php

<?php

declare(strict_types=1);
/**
 * Hoa
 *
 *
 * @license
 *
 * New BSD License
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 *       used to endorse or promote products derived from this software without
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namespace Hoa\Math\Test\Unit\Combinatorics\Combination;

use Hoa\Math\Combinatorics\Combination\CartesianProduct as CUT;
use Hoa\Test;

/**
 * Class \Hoa\Math\Test\Unit\Combinatorics\Combination\CartesianProduct.
 *
 * Test suite of the cartesian product.
 *
 * @license    New BSD License
 */
class CartesianProduct extends Test\Unit\Suite
{
    public function case_empty(): void
    {
        $this
            ->given($iterator = new CUT([]))
            ->when($result = iterator_to_array($iterator))
            ->then
                ->array($result)
                    ->isEqualTo([[null]]);
    }

    public function case_X(): void
    {
        $this
            ->given($iterator = new CUT([1, 2, 3]))
            ->when($result = iterator_to_array($iterator))
            ->then
                ->array($result)
                    ->isEqualTo([
                        [1],
                        [2],
                        [3]
                    ]);
    }

    public function case_X_Y(): void
    {
        $this
            ->given($iterator = new CUT([1, 2, 3], [4, 5, 6]))
            ->when($result = iterator_to_array($iterator))
            ->then
                ->array($result)
                    ->isEqualTo([
                        [1, 4],
                        [2, 4],
                        [3, 4],

                        [1, 5],
                        [2, 5],
                        [3, 5],

                        [1, 6],
                        [2, 6],
                        [3, 6]
                    ]);
    }

    public function case_X_Y_Z(): void
    {
        $this
            ->given($iterator = new CUT([1, 2, 3], [4, 5, 6], [7, 8, 9]))
            ->when($result = iterator_to_array($iterator))
            ->then
                ->array($result)
                    ->isEqualTo([
                        [1, 4, 7],
                        [2, 4, 7],
                        [3, 4, 7],
                        [1, 5, 7],
                        [2, 5, 7],
                        [3, 5, 7],
                        [1, 6, 7],
                        [2, 6, 7],
                        [3, 6, 7],

                        [1, 4, 8],
                        [2, 4, 8],
                        [3, 4, 8],
                        [1, 5, 8],
                        [2, 5, 8],
                        [3, 5, 8],
                        [1, 6, 8],
                        [2, 6, 8],
                        [3, 6, 8],

                        [1, 4, 9],
                        [2, 4, 9],
                        [3, 4, 9],
                        [1, 5, 9],
                        [2, 5, 9],
                        [3, 5, 9],
                        [1, 6, 9],
                        [2, 6, 9],
                        [3, 6, 9]
                    ]);
    }
}