Implementation Stable marriage problem in PHP (#428)

Author: PudottaPommin

contents/stable_marriage_problem/code/php/stable_marriage.php

@@ -0,0 +1,142 @@
+<?php
+declare(strict_types=1);
+
+class Person
+{
+    private $name;
+    private $suitors = [];
+    private $preferences = [];
+    private $match;
+
+    public function __construct($name)
+    {
+        $this->name = $name;
+    }
+
+    public function getName(): string
+    {
+        return $this->name;
+    }
+
+    public function setPreferences(array $preferences): void
+    {
+        $this->preferences = $preferences;
+    }
+
+    public function getMatch(): ?Person
+    {
+        return $this->match;
+    }
+
+    public function getPreferences(): array
+    {
+        return $this->preferences;
+    }
+
+    public function isSingle(): bool
+    {
+        return $this->match === null;
+    }
+
+    public function unmatch(): void
+    {
+        $this->match = null;
+    }
+
+    public function setMatch(Person $match): void
+    {
+        if ($this->match !== $match) {
+            if ($this->match !== null) {
+                $this->match->unmatch();
+            }
+            $this->match = $match;
+            $match->setMatch($this);
+        }
+    }
+
+    public function propose(): void
+    {
+        if (!empty($this->preferences)) {
+            $fiance = array_shift($this->preferences);
+            $fiance->receiveProposal($this);
+        }
+    }
+
+    public function receiveProposal(Person $man): void
+    {
+        $this->suitors[] = $man;
+    }
+
+    public function chooseMatch(): void
+    {
+        foreach ($this->preferences as $preference) {
+            if ($preference === $this->match || in_array($preference, $this->suitors)) {
+                $this->setMatch($preference);
+                break;
+            }
+        }
+
+        $this->suitors = [];
+    }
+
+    public function __toString(): string
+    {
+        return $this->name;
+    }
+}
+
+function stable_marriage(array $men, array $women): void
+{
+    do {
+        foreach ($men as $man) {
+            if ($man->isSingle()) {
+                $man->propose();
+            }
+        }
+
+        foreach ($women as $woman) {
+            $woman->chooseMatch();
+        }
+
+        $unmarried = false;
+        foreach ($women as $woman) {
+            if ($woman->isSingle()) {
+                $unmarried = true;
+                break;
+            }
+        }
+
+    } while ($unmarried);
+}
+
+$groupSize = 10;
+$men = [];
+$women = [];
+
+for ($i = 1; $i <= $groupSize; $i++) {
+    $men[] = new Person("M${i}");
+    $women[] = new Person("W${i}");
+}
+
+foreach ($men as $man) {
+    $preferences = $women;
+    shuffle($preferences);
+    $man->setPreferences($preferences);
+    printf('%s\'s choices: %s', $man->getName(), implode(',', $man->getPreferences()));
+    echo PHP_EOL;
+}
+echo PHP_EOL;
+foreach ($women as $woman) {
+    $preferences = $men;
+    shuffle($preferences);
+    $woman->setPreferences($preferences);
+    printf('%s\'s choices: %s', $woman->getName(), implode(',', $woman->getPreferences()));
+    echo PHP_EOL;
+}
+echo PHP_EOL;
+
+stable_marriage($men, $women);
+foreach ($women as $woman) {
+    printf('%s is married to %s', $woman, $woman->getMatch());
+    echo PHP_EOL;
+}

contents/stable_marriage_problem/stable_marriage_problem.md

@@ -44,6 +44,8 @@ I am incredibly interested to see what you guys do and how you implement the alg
 [import, lang:"csharp"](code/csharp/ListExtensions.cs)
 {% sample lang="java" %}
 [import, lang:"java"](code/java/stable-marriage.java)
+{% sample lang="php" %}
+[import, lang:"php"](code/php/stable_marriage.php)
 {% endmethod %}
 
 <script>