WIP

src/Simplex/Dumper.php

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+<?php
+
+declare(strict_types = 1);
+
+/**
+ * This file is part of the Simplex-Calculator library
+ *
+ * Copyright (c) 2014 Petr Kessler (https://kesspess.cz)
+ *
+ * @license  MIT
+ * @link     https://github.com/uestla/Simplex-Calculator
+ */
+
+namespace Simplex;
+
+use Simplex\Math\Vector;
+use Simplex\Math\Fraction;
+use Simplex\Task\InitialTask;
+use Simplex\Task\StandardTask;
+
+
+final class Dumper
+{
+	public static function dump(mixed $v): void
+	{
+		if ($v instanceof Fraction) {
+			self::dumpFraction($v);
+
+		} elseif ($v instanceof Vector) {
+			self::dumpVector($v);
+
+		} elseif ($v instanceof InitialTask) {
+			self::dumpInitialTask($v);
+
+		} elseif ($v instanceof StandardTask) {
+			// self::dumpStandardTask($v);
+
+		} else {
+			throw new \InvalidArgumentException(sprintf('Cannot dump variable of type %s', is_object($v) ? get_class($v) : gettype($v)));
+		}
+	}
+
+
+	private static function dumpFraction(Fraction $f): void
+	{
+		echo $f;
+	}
+
+
+	private static function dumpVector(Vector $v): void
+	{
+		echo '[', implode(', ', $v->toArray()), ']';
+	}
+
+
+	private static function dumpInitialTask(InitialTask $t): void
+	{
+		echo 'f: '; // TODO
+	}
+}

src/Simplex/Solution.php

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+<?php
+
+declare(strict_types = 1);
+
+/**
+ * This file is part of the Simplex-Calculator library
+ *
+ * Copyright (c) 2014 Petr Kessler (https://kesspess.cz)
+ *
+ * @license  MIT
+ * @link     https://github.com/uestla/Simplex-Calculator
+ */
+
+namespace Simplex;
+
+use Simplex\Math\Vector;
+use Simplex\Tableau\Tableau;
+
+
+final class Solution
+{
+	/** @var Tableau[] */
+	private array $tableaus;
+
+	private Vector $values;
+
+	private ?Vector $alternativeValues;
+
+
+	/** @param  Tableau[] $tableaus */
+	public function __construct(array $tableaus, Vector $values, ?Vector $alternativeValues)
+	{
+		$this->values = $values;
+		$this->tableaus = $tableaus;
+		$this->alternativeValues = $alternativeValues;
+	}
+
+
+	/** @return Tableau[] */
+	public function getTableaus(): array
+	{
+		return $this->tableaus;
+	}
+
+
+	public function getValues(): Vector
+	{
+		return $this->values;
+	}
+
+
+	public function getAlternativeValues(): ?Vector
+	{
+		return $this->alternativeValues;
+	}
+}

src/Simplex/Solver.php

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+<?php
+
+declare(strict_types = 1);
+
+/**
+ * This file is part of the Simplex-Calculator library
+ *
+ * Copyright (c) 2014 Petr Kessler (https://kesspess.cz)
+ *
+ * @license  MIT
+ * @link     https://github.com/uestla/Simplex-Calculator
+ */
+
+namespace Simplex;
+
+use Simplex\Math\Vector;
+use Simplex\Task\InitialTask;
+
+
+final class Solver
+{
+	private readonly int $maxSteps;
+
+
+	public function __construct(int $maxSteps = 128)
+	{
+		$this->maxSteps = $maxSteps;
+	}
+
+
+	public function maximize(InitialTask $task): Solution
+	{
+		$standardTask = $task->toStandardTask();
+		$tableau = $standardTask->toTableau();
+
+		dumpe($tableau, ':OOO');
+
+		$tableaus = [];
+		while (count($tableaus) < $this->maxSteps) {
+			$tableaus[] = $tableau;
+
+			dumpe($tableau, ':OOO');
+		}
+
+		dumpe($standardTask);
+
+		// TODO: throw exception when solution not found in under $maxSteps steps?
+
+		return new Solution([], new Vector([]), null);
+	}
+
+
+	public function minimize(InitialTask $task): Solution
+	{
+		// TODO
+
+		return new Solution([], new Vector([]), null);
+	}
+}

src/Simplex/Tableau/Tableau.php

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+<?php
+
+declare(strict_types = 1);
+
+/**
+ * This file is part of the Simplex-Calculator library
+ *
+ * Copyright (c) 2014 Petr Kessler (https://kesspess.cz)
+ *
+ * @license  MIT
+ * @link     https://github.com/uestla/Simplex-Calculator
+ */
+
+namespace Simplex\Tableau;
+
+use Simplex\Math\Fraction;
+
+
+final class Tableau
+{
+	/** @var array<int, array<int, Fraction>> */
+	private array $rows = [];
+
+	/** @var array<int, true> */
+	private readonly array $surplusVars;
+
+	private readonly bool $hasSurplusVarInBasis;
+
+
+	/** @param  array<int, true> $surplusVars */
+	public function __construct(array $surplusVars, bool $hasSurplusVarInBasis)
+	{
+		$this->surplusVars = $surplusVars;
+		$this->hasSurplusVarInBasis = $hasSurplusVarInBasis;
+	}
+
+
+	/** @param  array<int, Fraction> $values */
+	public function addRow(int $varIdx, array $values): void
+	{
+		$this->rows[$varIdx] = $values;
+	}
+
+
+	public function isFinished(): bool
+	{
+		$lastRow = $this->getLastRow();
+
+		if ($lastRow === null) {
+			// TODO: no solution
+			return true;
+		}
+
+		if ($this->hasSurplusVarInBasis) {
+			foreach ($lastRow as $value) {
+				if ($value->isNegative()) {
+					return false;
+				}
+			}
+		}
+
+		reset($lastRow);
+		$keyVarIdx = key($lastRow);
+		$keyVal = current($lastRow);
+
+		foreach ($lastRow as $varIdx => $value) {
+			if ($value->isLowerThan($keyVal)) {
+				$keyVal = $value;
+				$keyVarIdx = $varIdx;
+			}
+		}
+
+		if ($keyVal->isNegative()) {
+			foreach ($this->rows as $row) {
+				if ($row[$keyVarIdx]->isPositive()) {
+					return false;
+				}
+			}
+
+			// TODO: no solution
+		}
+
+		return true;
+	}
+
+
+	/** @return array<int, Fraction>|null */
+	private function getLastRow(): ?array
+	{
+		return end($this->rows) ?: null;
+	}
+}

src/Simplex/Task/Constraint/Constraint.php

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+<?php
+
+declare(strict_types = 1);
+
+/**
+ * This file is part of the Simplex-Calculator library
+ *
+ * Copyright (c) 2014 Petr Kessler (https://kesspess.cz)
+ *
+ * @license  MIT
+ * @link     https://github.com/uestla/Simplex-Calculator
+ */
+
+namespace Simplex\Task\Constraint;
+
+use Simplex\Math\Vector;
+use Simplex\Math\Fraction;
+
+
+abstract class Constraint
+{
+	private readonly Vector $coeffs;
+	private readonly Fraction $value;
+
+
+	/** @param Vector|array<int, Fraction|string|int|float> $coeffs */
+	public function __construct(Vector|array $coeffs, Fraction|string|int|float $value)
+	{
+		$this->coeffs = Vector::create($coeffs);
+		$this->value = Fraction::create($value);
+	}
+
+
+	public function getCoeffs(): Vector
+	{
+		return $this->coeffs;
+	}
+
+
+	public function getValue(): Fraction
+	{
+		return $this->value;
+	}
+}

src/Simplex/Task/Constraint/Equal.php

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+<?php
+
+declare(strict_types = 1);
+
+/**
+ * This file is part of the Simplex-Calculator library
+ *
+ * Copyright (c) 2014 Petr Kessler (https://kesspess.cz)
+ *
+ * @license  MIT
+ * @link     https://github.com/uestla/Simplex-Calculator
+ */
+
+namespace Simplex\Task\Constraint;
+
+
+final class Equal extends Constraint
+{}

src/Simplex/Task/Constraint/GreaterOrEqual.php

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+<?php
+
+declare(strict_types = 1);
+
+/**
+ * This file is part of the Simplex-Calculator library
+ *
+ * Copyright (c) 2014 Petr Kessler (https://kesspess.cz)
+ *
+ * @license  MIT
+ * @link     https://github.com/uestla/Simplex-Calculator
+ */
+
+namespace Simplex\Task\Constraint;
+
+
+final class GreaterOrEqual extends Constraint
+{}

src/Simplex/Task/Constraint/LowerOrEqual.php

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+<?php
+
+declare(strict_types = 1);
+
+/**
+ * This file is part of the Simplex-Calculator library
+ *
+ * Copyright (c) 2014 Petr Kessler (https://kesspess.cz)
+ *
+ * @license  MIT
+ * @link     https://github.com/uestla/Simplex-Calculator
+ */
+
+namespace Simplex\Task\Constraint;
+
+
+final class LowerOrEqual extends Constraint
+{}