drupol\phpermutations\Iterators\Combinations

Complexity

Total Complexity

14

Size/Duplication

Total Lines	109
Duplicated Lines	0 %

Test Coverage

Coverage

100%

Importance

Changes	3
Bugs	0	Features	0

7 Methods

Rating	Name	Duplication	Size	Complexity
A	nextHelper()	0	19	5
A	next()	0	6	2
A	rewind()	0	4	1
A	valid()	0	3	1
A	current()	0	9	2
A	__construct()	0	4	1
A	count()	0	9	2

<?php

declare(strict_types=1);

namespace drupol\phpermutations\Iterators;

use drupol\phpermutations\Iterators;

class Combinations extends Iterators
{
    /**
     * The values.
     *
     * @var array<int, mixed>
     */
    protected $c = [];

    /**
     * Combinations constructor.
     *
     * @param array<int, mixed> $dataset
     *                          The dataset
     * @param int|null $length
     *                          The length
     */
    public function __construct(array $dataset = [], $length = null)
    {
        parent::__construct(array_values($dataset), $length);
        $this->rewind();
    }

    /**
     * {@inheritdoc}
     */
    public function count(): int
    {
        $i = 0;

        for ($this->rewind(); $this->valid(); $this->next()) {
            ++$i;
        }

        return $i;
    }

    /**
     * {@inheritdoc}
     */
    public function current(): mixed
    {
        $r = [];

        for ($i = 0; $i < $this->length; ++$i) {
            $r[] = $this->dataset[$this->c[$i]];
        }

        return $r;
    }

    /**
     * {@inheritdoc}
     *
     * @return void
     */
    public function next(): void
    {
        if ($this->nextHelper()) {
            ++$this->key;
        } else {
            $this->key = -1;
        }
    }

    /**
     * {@inheritdoc}
     */
    public function rewind(): void
    {
        $this->c = range(0, $this->length);
        $this->key = 0;
    }

    /**
     * {@inheritdoc}
     *
     * @return bool
     */
    public function valid(): bool
    {
        return 0 <= $this->key;
    }

    /**
     * Custom next() callback.
     *
     * @return bool
     *              Return true or false
     */
    protected function nextHelper(): bool
    {
        $i = $this->length - 1;

        while (0 <= $i && $this->datasetCount - $this->length + $i === $this->c[$i]) {
            --$i;
        }

        if (0 > $i) {
            return false;
        }

        ++$this->c[$i];

        while ($this->length - 1 > $i++) {
            $this->c[$i] = $this->c[$i - 1] + 1;
        }

        return true;
    }
}