feat: Refactor ArrayQueue, Create CircularArrayQueue, Refactor ArrayD…

src/Queue/ArrayDeque.php

@@ -4,6 +4,7 @@
 
 namespace KaririCode\DataStructure\Queue;
 
+use KaririCode\Contract\DataStructure\Deque;
 use KaririCode\Contract\DataStructure\Queue;
 
 /**
@@ -16,45 +17,9 @@
  *
  * @implements Queue<mixed>
  */
-class ArrayDeque implements Queue
-{
-    private array $elements;
-    private int $front = 0;
-    private int $size = 0;
-    private int $capacity;
-
-    public function __construct(int $initialCapacity = 16)
-    {
-        $this->capacity = $initialCapacity;
-        $this->elements = array_fill(0, $this->capacity, null);
-    }
-
-    public function enqueue(mixed $element): void
-    {
-        $this->ensureCapacity();
-        $index = ($this->front + $this->size) % $this->capacity;
-        $this->elements[$index] = $element;
-        ++$this->size;
-    }
-
-    public function dequeue(): mixed
-    {
-        if ($this->isEmpty()) {
-            return null;
-        }
-        $element = $this->elements[$this->front];
-        $this->elements[$this->front] = null;
-        $this->front = ($this->front + 1) % $this->capacity;
-        --$this->size;
-
-        return $element;
-    }
-
-    public function peek(): mixed
-    {
-        return $this->isEmpty() ? null : $this->elements[$this->front];
-    }
 
+class ArrayDeque extends CircularArrayQueue implements Deque
+{
     public function addFirst(mixed $element): void
     {
         $this->ensureCapacity();
@@ -85,31 +50,4 @@ public function peekLast(): mixed
 
         return $this->elements[$index];
     }
-
-    public function isEmpty(): bool
-    {
-        return 0 === $this->size;
-    }
-
-    public function size(): int
-    {
-        return $this->size;
-    }
-
-    /**
-     * Ensures that the deque has enough capacity to add a new element.
-     */
-    private function ensureCapacity(): void
-    {
-        if ($this->size === $this->capacity) {
-            $newCapacity = $this->capacity * 2;
-            $newElements = array_fill(0, $newCapacity, null);
-            for ($i = 0; $i < $this->size; ++$i) {
-                $newElements[$i] = $this->elements[($this->front + $i) % $this->capacity];
-            }
-            $this->elements = $newElements;
-            $this->front = 0;
-            $this->capacity = $newCapacity;
-        }
-    }
 }

src/Queue/ArrayQueue.php

@@ -19,69 +19,8 @@
  *
  * @see       https://kariricode.org/
  */
-class ArrayQueue implements Queue
-{
-    private array $elements;
-    private int $front = 0;
-    private int $size = 0;
-    private int $capacity;
-
-    public function __construct(int $initialCapacity = 16)
-    {
-        $this->capacity = $initialCapacity;
-        $this->elements = array_fill(0, $this->capacity, null);
-    }
-
-    public function enqueue(mixed $element): void
-    {
-        $this->ensureCapacity();
-        $index = ($this->front + $this->size) % $this->capacity;
-        $this->elements[$index] = $element;
-        ++$this->size;
-    }
-
-    public function dequeue(): mixed
-    {
-        if ($this->isEmpty()) {
-            return null;
-        }
-        $element = $this->elements[$this->front];
-        $this->elements[$this->front] = null;
-        $this->front = ($this->front + 1) % $this->capacity;
-        --$this->size;
-
-        return $element;
-    }
 
-    public function peek(): mixed
-    {
-        return $this->isEmpty() ? null : $this->elements[$this->front];
-    }
-
-    public function isEmpty(): bool
-    {
-        return 0 === $this->size;
-    }
-
-    public function size(): int
-    {
-        return $this->size;
-    }
-
-    /**
-     * Ensures that the queue has enough capacity to add a new element.
-     */
-    private function ensureCapacity(): void
-    {
-        if ($this->size === $this->capacity) {
-            $newCapacity = $this->capacity * 2;
-            $newElements = array_fill(0, $newCapacity, null);
-            for ($i = 0; $i < $this->size; ++$i) {
-                $newElements[$i] = $this->elements[($this->front + $i) % $this->capacity];
-            }
-            $this->elements = $newElements;
-            $this->front = 0;
-            $this->capacity = $newCapacity;
-        }
-    }
+class ArrayQueue extends CircularArrayQueue implements Queue
+{
+    // No additional methods required, uses methods from CircularArrayQueue
 }

src/Queue/CircularArrayQueue.php

@@ -0,0 +1,99 @@
+<?php
+
+declare(strict_types=1);
+
+namespace KaririCode\DataStructure\Queue;
+
+use KaririCode\Contract\DataStructure\Queue;
+
+/**
+ * CircularArrayQueue implementation.
+ *
+ * This class provides the common functionality for array-based queues using a circular array.
+ *
+ * @category  Queues
+ *
+ * @author    Walmir Silva <walmir.silva@kariricode.org>
+ * @license   MIT
+ *
+ * @see       https://kariricode.org/
+ */
+abstract class CircularArrayQueue implements Queue
+{
+    protected array $elements;
+    protected int $front = 0;
+    protected int $size = 0;
+    protected int $capacity;
+
+    public function __construct(int $initialCapacity = 16)
+    {
+        $this->capacity = $initialCapacity;
+        $this->elements = array_fill(0, $this->capacity, null);
+    }
+
+    public function isEmpty(): bool
+    {
+        return $this->size === 0;
+    }
+
+    public function size(): int
+    {
+        return $this->size;
+    }
+
+    public function clear(): void
+    {
+        $this->elements = array_fill(0, $this->capacity, null);
+        $this->front = 0;
+        $this->size = 0;
+    }
+
+    protected function ensureCapacity(): void
+    {
+        if ($this->size === $this->capacity) {
+            $newCapacity = $this->capacity * 2;
+            $newElements = array_fill(0, $newCapacity, null);
+            for ($i = 0; $i < $this->size; ++$i) {
+                $newElements[$i] = $this->elements[($this->front + $i) % $this->capacity];
+            }
+            $this->elements = $newElements;
+            $this->front = 0;
+            $this->capacity = $newCapacity;
+        }
+    }
+
+    public function peek(): mixed
+    {
+        return $this->isEmpty() ? null : $this->elements[$this->front];
+    }
+
+    public function dequeue(): mixed
+    {
+        if ($this->isEmpty()) {
+            return null;
+        }
+        $element = $this->elements[$this->front];
+        $this->elements[$this->front] = null;
+        $this->front = ($this->front + 1) % $this->capacity;
+        --$this->size;
+
+        return $element;
+    }
+
+    public function enqueue(mixed $element): void
+    {
+        $this->ensureCapacity();
+        $index = ($this->front + $this->size) % $this->capacity;
+        $this->elements[$index] = $element;
+        ++$this->size;
+    }
+
+    public function getItems(): array
+    {
+        $items = [];
+        for ($i = 0; $i < $this->size; ++$i) {
+            $items[] = $this->elements[($this->front + $i) % $this->capacity];
+        }
+        return $items;
+    }
+}

tests/Queue/ArrayDequeTest.php

@@ -172,4 +172,69 @@ public function testDequeBehaviorAfterMixedOperations(): void
         $this->assertSame(1, $deque->dequeue());
         $this->assertSame(3, $deque->peekLast());
     }
+
+    // Test capacity expansion during addFirst operations
+    public function testEnsureCapacityExpandsDuringAddFirstOperations(): void
+    {
+        $deque = new ArrayDeque(2);
+        $deque->addFirst(1);
+        $deque->addFirst(2);
+        $deque->addFirst(3); // Should trigger capacity increase
+        $this->assertSame(3, $deque->size());
+        $this->assertSame(3, $deque->peek());
+        $this->assertSame(1, $deque->peekLast());
+    }
+
+    // Test capacity expansion during removeLast operations
+    public function testEnsureCapacityExpandsDuringRemoveLastOperations(): void
+    {
+        $deque = new ArrayDeque(2);
+        $deque->enqueue(1);
+        $deque->enqueue(2);
+        $deque->enqueue(3); // Should trigger capacity increase
+        $deque->removeLast();
+        $deque->removeLast();
+        $this->assertSame(1, $deque->size());
+        $this->assertSame(1, $deque->peek());
+    }
+
+    // Test mixed operations of addFirst, addLast, removeFirst, and removeLast
+    public function testMixedOperations(): void
+    {
+        $deque = new ArrayDeque();
+        $deque->addFirst(1);
+        $deque->enqueue(2);
+        $deque->addFirst(0);
+        $this->assertSame(0, $deque->dequeue());
+        $this->assertSame(1, $deque->dequeue());
+        $this->assertSame(2, $deque->removeLast());
+        $deque->enqueue(3);
+        $deque->addFirst(4);
+        $this->assertSame(4, $deque->peek());
+        $this->assertSame(3, $deque->peekLast());
+    }
+
+    // Test clearing the deque
+    public function testClearEmptiesTheDeque(): void
+    {
+        $deque = new ArrayDeque();
+        $deque->enqueue(1);
+        $deque->enqueue(2);
+        $deque->clear();
+        $this->assertTrue($deque->isEmpty());
+        $this->assertNull($deque->peek());
+        $this->assertNull($deque->peekLast());
+        $this->assertNull($deque->dequeue());
+        $this->assertNull($deque->removeLast());
+    }
+
+    // Test getting all items
+    public function testGetItemsReturnsAllElementsInCorrectOrder(): void
+    {
+        $deque = new ArrayDeque();
+        $deque->enqueue(1);
+        $deque->enqueue(2);
+        $deque->enqueue(3);
+        $this->assertSame([1, 2, 3], $deque->getItems());
+    }
 }