Permutator::getPermutations() - Code Metrics - Inspection of "Merge pull request #18 from byrokrat/2.0" - byrokrat/banking - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 5d18c7...cabcf3 )

by Hannes

created 2018-06-07 16:01 UTC

Permutator::getPermutations() A

↳ Parent: Permutator

Complexity

Conditions	3
Paths	3

Size

Total Lines	8
Code Lines	4

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	5
CRAP Score	3

Importance

Changes

Metric	Value
cc	3
eloc	4
nc	3
nop	1
dl	0
loc	8
rs	9.4285
c	0
b	0
f	0
ccs	5
cts	5
cp	1
crap	3

<?php

declare(strict_types = 1);

namespace byrokrat\banking\Rewriter;

/**
 * Generate permutations for a set of values
 */
class Permutator
{
    /**
     * @return \Generator & iterable<array>
     */
    public static function getPermutations(array $set): \Generator
    {
        foreach (self::getPowerSet($set) as $subset) {
            foreach (self::generateFixedLengthPermutations($subset) as $perm) {
                yield $perm;
            }
        }
    }

    /**
     * @return array[]
     */
    private static function getPowerSet(array $set): array
    {
        $results = [[]];

        foreach ($set as $element) {
            foreach ($results as $combination) {
                $subset = array_merge([$element], $combination);
                $results[] = $subset;
            }
        }

        usort(
            $results,
            function (array $left, array $right): int {
                return count($left) <=> count($right);
            }
        );

        return array_filter($results);
    }

    /**
     * @return \Generator & iterable<array>
     */
    private static function generateFixedLengthPermutations(array $items, array $perms = []): \Generator
    {
        if (empty($items)) {
            yield $perms;
        } else {
            for ($i = count($items)-1; $i>=0; $i--) {
                $newitems = $items;
                $newperms = $perms;
                list($foo) = array_splice($newitems, $i, 1);
                array_unshift($newperms, $foo);
                yield from self::generateFixedLengthPermutations($newitems, $newperms);
            }
        }
    }
}


1		<?php
2
3		declare(strict_types = 1);
4
5		namespace byrokrat\banking\Rewriter;
6
7		/**
8		* Generate permutations for a set of values
9		*/
10		class Permutator
11		{
12		/**
13		* @return \Generator & iterable<array>
14		*/
15	142	public static function getPermutations(array $set): \Generator
16		{
17	142	foreach (self::getPowerSet($set) as $subset) {
18	142	foreach (self::generateFixedLengthPermutations($subset) as $perm) {
19	142	yield $perm;
20		}
21		}
22	59	}
23
24		/**
25		* @return array[]
26		*/
27	142	private static function getPowerSet(array $set): array
28		{
29	142	$results = [[]];
30
31	142	foreach ($set as $element) {
32	142	foreach ($results as $combination) {
33	142	$subset = array_merge([$element], $combination);
34	142	$results[] = $subset;
35		}
36		}
37
38	142	usort(
39	142	$results,
40	142	function (array $left, array $right): int {
41	142	return count($left) <=> count($right);
42	142	}
43		);
44
45	142	return array_filter($results);
46		}
47
48		/**
49		* @return \Generator & iterable<array>
50		*/
51	142	private static function generateFixedLengthPermutations(array $items, array $perms = []): \Generator
52		{
53	142	if (empty($items)) {
54	142	yield $perms;
55		} else {
56	142	for ($i = count($items)-1; $i>=0; $i--) {
57	142	$newitems = $items;
58	142	$newperms = $perms;
59	142	list($foo) = array_splice($newitems, $i, 1);
60	142	array_unshift($newperms, $foo);
61	142	yield from self::generateFixedLengthPermutations($newitems, $newperms);
62		}
63		}
64	142	}
65		}
66

byrokrat / banking

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Permutator::getPermutations() A

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