diff options
author | Andrew Dolgov <[email protected]> | 2022-03-22 12:24:31 +0300 |
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committer | Andrew Dolgov <[email protected]> | 2022-03-22 12:24:31 +0300 |
commit | 1c4f7ab3b838b23afb2ee4dab14acbf75956e952 (patch) | |
tree | 0a19274107d717efe92d2c0376cd3105fead5a11 /vendor/sebastian/diff/src/MemoryEfficientLongestCommonSubsequenceCalculator.php | |
parent | 711662948768492e8d05b778a7d80eacaec368d2 (diff) |
* add phpunit as a dev dependency
* add some basic tests for UrlHelper::rewrite_relative()
* fix UrlHelper::rewrite_relative() to work better on non-absolute
relative URL paths
Diffstat (limited to 'vendor/sebastian/diff/src/MemoryEfficientLongestCommonSubsequenceCalculator.php')
-rw-r--r-- | vendor/sebastian/diff/src/MemoryEfficientLongestCommonSubsequenceCalculator.php | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/vendor/sebastian/diff/src/MemoryEfficientLongestCommonSubsequenceCalculator.php b/vendor/sebastian/diff/src/MemoryEfficientLongestCommonSubsequenceCalculator.php new file mode 100644 index 000000000..0b626eaff --- /dev/null +++ b/vendor/sebastian/diff/src/MemoryEfficientLongestCommonSubsequenceCalculator.php @@ -0,0 +1,88 @@ +<?php declare(strict_types=1); +/* + * This file is part of sebastian/diff. + * + * (c) Sebastian Bergmann <[email protected]> + * + * For the full copyright and license information, please view the LICENSE + * file that was distributed with this source code. + */ +namespace SebastianBergmann\Diff; + +use function array_fill; +use function array_merge; +use function array_reverse; +use function array_slice; +use function count; +use function in_array; +use function max; + +final class MemoryEfficientLongestCommonSubsequenceCalculator implements LongestCommonSubsequenceCalculator +{ + /** + * {@inheritdoc} + */ + public function calculate(array $from, array $to): array + { + $cFrom = count($from); + $cTo = count($to); + + if ($cFrom === 0) { + return []; + } + + if ($cFrom === 1) { + if (in_array($from[0], $to, true)) { + return [$from[0]]; + } + + return []; + } + + $i = (int) ($cFrom / 2); + $fromStart = array_slice($from, 0, $i); + $fromEnd = array_slice($from, $i); + $llB = $this->length($fromStart, $to); + $llE = $this->length(array_reverse($fromEnd), array_reverse($to)); + $jMax = 0; + $max = 0; + + for ($j = 0; $j <= $cTo; $j++) { + $m = $llB[$j] + $llE[$cTo - $j]; + + if ($m >= $max) { + $max = $m; + $jMax = $j; + } + } + + $toStart = array_slice($to, 0, $jMax); + $toEnd = array_slice($to, $jMax); + + return array_merge( + $this->calculate($fromStart, $toStart), + $this->calculate($fromEnd, $toEnd) + ); + } + + private function length(array $from, array $to): array + { + $current = array_fill(0, count($to) + 1, 0); + $cFrom = count($from); + $cTo = count($to); + + for ($i = 0; $i < $cFrom; $i++) { + $prev = $current; + + for ($j = 0; $j < $cTo; $j++) { + if ($from[$i] === $to[$j]) { + $current[$j + 1] = $prev[$j] + 1; + } else { + $current[$j + 1] = max($current[$j], $prev[$j + 1]); + } + } + } + + return $current; + } +} |