drupol\phpermutations\Permutations

Complexity

Total Complexity

15

Size/Duplication

Total Lines	89
Duplicated Lines	0 %

Coupling/Cohesion

Dependencies

2

Test Coverage

Coverage

100%

Importance

Changes

0

5 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	3	1
A	count()	0	3	1
B	generator()	0	22	5
B	permute()	0	23	6
A	toArray()	0	9	2

<?php

namespace drupol\phpermutations;

/**
 * Class Permutations.
 *
 * @package drupol\phpermutations
 */
class Permutations extends Combinatorics {

  /**
   * Permutations constructor.
   *
   * @param array $dataset
   * @param int $length

Should the type for parameter $length not be integer|null?

   */
  public function __construct(array $dataset = array(), $length = NULL) {

TRUE, FALSE and NULL must be lowercase; expected null, but found NULL.

    parent::__construct($dataset, $length);
  }

  /**
   * @return int
   */
  public function count() {
    return $this->fact(count($this->getDataset())) / $this->fact(count($this->getDataset()) - $this->getLength());
  }

  /**
   * @return \Generator

Should the return type not be array? Also, consider making the array more specific, something like array<String>, or String[].

   */
  public function generator() {
    $combinations = new Combinations($this->getDataset(), $this->getLength());
    $result = array();

    foreach ($combinations->toArray() as $subset) {
      $set = $subset;
      $perms = array();
      $size = count($subset) - 1;
      $perm = range(0, $size);
      $j = 0;

      do {
        foreach ($perm as $i) {
          $perms[$j][] = $set[$i];
        }
      } while ($perm = $this->permute($perm, $size) and ++$j);

      $result = array_merge($result, $perms);
    }

    return $result;
  }

  /**
   * @param $items
   * @param array $perms

There is no parameter named $perms. Was it maybe removed?

   *
   * @return array

Should the return type not be false|array? Also, consider making the array more specific, something like array<String>, or String[].

   */
  protected function permute($p, $size) {

Avoid variables with short names like $p. Configured minimum length is 3.

    // slide down the array looking for where we're smaller than the next guy
    for ($i = $size - 1; $i >= 0 && $p[$i] >= $p[$i+1]; --$i) { }

    // if this doesn't occur, we've finished our permutations
    // the array is reversed: (1, 2, 3, 4) => (4, 3, 2, 1)
    if ($i == -1) {
      return false;
    }

    // slide down the array looking for a bigger number than what we found before
    for ($j = $size; $p[$j] <= $p[$i]; --$j) { }

    // swap them
    $tmp = $p[$i]; $p[$i] = $p[$j]; $p[$j] = $tmp;

It is generally recommended to place each PHP statement on a line by itself.

    // now reverse the elements in between by swapping the ends
    for (++$i, $j = $size; $i < $j; ++$i, --$j) {
      $tmp = $p[$i]; $p[$i] = $p[$j]; $p[$j] = $tmp;

It is generally recommended to place each PHP statement on a line by itself.

    }

    return $p;
  }

  /**
   * @return array
   */
  public function toArray() {
    $results = array();

    foreach ($this->generator() as $value) {
      $results[] = $value;
    }

    return $results;
  }

}