fix linked list remove method

doganoo · Sep 28, 2019 · d16216e · d16216e
1 parent cf1bb17
commit d16216e
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Showing 4 changed files with 83 additions and 33 deletions.
diff --git a/src/Common/Abstracts/AbstractLinkedList.php b/src/Common/Abstracts/AbstractLinkedList.php
@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 /**
  * MIT License
  *
@@ -46,6 +47,7 @@
  *
  */
 abstract class AbstractLinkedList implements IComparable, JsonSerializable {
+
     /** @var Node */
     private $head = null;
 
@@ -74,14 +76,14 @@ abstract class AbstractLinkedList implements IComparable, JsonSerializable {
      *             5 -> 4 -> 3 -> 2 -> 1 -> NULL
      */
     public function reverse() {
-        $prev = null;
-        $next = null;
+        $prev    = null;
+        $next    = null;
         $current = $this->getHead();
 
         while ($current !== null) {
             $next = $current->getNext();
             $current->setNext($prev);
-            $prev = $current;
+            $prev    = $current;
             $current = $next;
         }
         $this->setHead($prev);
@@ -182,10 +184,10 @@ public function removeDuplicates() {
      *
      */
     public function getLastElements(int $number): AbstractLinkedList {
-        $p1 = $this->getHead();
-        $p2 = $this->getHead();
+        $p1     = $this->getHead();
+        $p2     = $this->getHead();
         $number = $number > $this->head->size() ? $this->head->size() : $number;
-        $list = $this->getEmptyInstance();
+        $list   = $this->getEmptyInstance();
 
         for ($i = 0; $i < $number; $i++) {
             if ($p1 == null) {
@@ -252,8 +254,8 @@ public function getFirstElements(int $number): AbstractLinkedList {
         $head = $this->getHead();
         //if there are more elements requested than the list provides
         $number = $number > $head->size() ? $head->size() : $number;
-        $list = $this->getEmptyInstance();
-        $i = 0;
+        $list   = $this->getEmptyInstance();
+        $i      = 0;
         while ($i < $number) {
             //TODO append or prepend?
             $list->append($head);
@@ -402,12 +404,20 @@ public function containsKey($key): bool {
      */
     public function remove($key): bool {
         /** @var Node $previous */
-        $previous = $head = $this->getHead();
+        $head     = $this->getHead();
+        $previous = null;
         if ($head === null) {
             return true;
         }
+
+        if (Comparator::equals($head->getKey(), $key)) {
+            $this->setHead(
+                $head->getNext()
+            );
+            return true;
+        }
+
         $i = 1;
-        $headSize = $head->size();
 
         /*
          * The while loop iterates over all nodes until the
@@ -428,10 +438,13 @@ public function remove($key): bool {
              * after that one who should be deleted.
              */
             $previous = $head;
-            $head = $head->getNext();
+            $head     = $head->getNext();
             $i++;
         }
 
+        if (null === $head) {
+            return false;
+        }
         /*
          * If the value that should be deleted is not in the list,
          * this set instruction assigns the next node to the actual.
@@ -440,10 +453,8 @@ public function remove($key): bool {
          * assigned to the previous node of the node that
          * should be deleted (if there is a node present).
          */
-        if ($head !== null) {
-            $previous->setNext($head->getNext());
-        }
-        return $i !== $headSize;
+        $previous->setNext($head->getNext());
+        return true;
     }
 
     /**
@@ -455,7 +466,7 @@ public function remove($key): bool {
      */
     public function replaceValue($key, $value): bool {
         $replaced = false;
-        $node = $this->getHead();
+        $node     = $this->getHead();
         while ($node !== null) {
             if (Comparator::equals($node->getKey(), $key)) {
                 $node->setValue($value);
@@ -486,7 +497,7 @@ public function compareTo($object): int {
      */
     public function hasLoop(): bool {
         $tortoise = $this->getHead();
-        $hare = $this->getHead();
+        $hare     = $this->getHead();
 
         while ($tortoise !== null && $hare->getNext() !== null) {
             $hare = $hare->getNext()->getNext();
@@ -596,7 +607,7 @@ public function isEmpty() {
     /**
      * Specify data which should be serialized to JSON
      *
-     * @link http://php.net/manual/en/jsonserializable.jsonserialize.php
+     * @link  http://php.net/manual/en/jsonserializable.jsonserialize.php
      * @return mixed data which can be serialized by <b>json_encode</b>,
      * which is a value of any type other than a resource.
      * @since 5.4.0

diff --git a/src/Datastructure/Table/HashTable.php b/src/Datastructure/Table/HashTable.php
@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 /**
  * MIT License
  *
@@ -50,6 +51,7 @@
  * @package doganoo\PHPAlgorithms\Maps
  */
 class HashTable extends AbstractTable implements JsonSerializable {
+
     /**
      * @var array $bucket the buckets containing the nodes
      */
@@ -136,7 +138,7 @@ private function getBucketIndex($key) {
          *
          * Doing this avoids hash collisions.
          */
-        $hash = $this->getHash($key);
+        $hash       = $this->getHash($key);
         $arrayIndex = $this->getArrayIndex($hash);
         return $arrayIndex;
     }
@@ -152,7 +154,7 @@ private function getBucketIndex($key) {
      */
     private function getHash($key): int {
         $key = MapUtil::normalizeKey($key);
-        return crc32($key);
+        return crc32((string) $key);
     }
 
     /**
@@ -226,7 +228,7 @@ public function getNodeByKey($key): ?Node {
     public function size(): int {
         $size = 0;
         /**
-         * @var string $hash
+         * @var string              $hash
          * @var  AbstractLinkedList $list
          */
         foreach ($this->bucket as $hash => $list) {
@@ -244,7 +246,7 @@ public function size(): int {
     public function containsValue($value): bool {
 
         /**
-         * @var string $arrayIndex
+         * @var string           $arrayIndex
          * @var SinglyLinkedList $list
          */
         foreach ($this->bucket as $arrayIndex => $list) {
@@ -272,7 +274,7 @@ public function containsValue($value): bool {
      */
     public function containsKey($key): bool {
         /**
-         * @var string $arrayIndex
+         * @var string           $arrayIndex
          * @var SinglyLinkedList $list
          */
         foreach ($this->bucket as $arrayIndex => $list) {
@@ -305,7 +307,7 @@ public function containsKey($key): bool {
      */
     public function getNodeByValue($value): ?Node {
         /**
-         * @var string $arrayIndex
+         * @var string           $arrayIndex
          * @var SinglyLinkedList $list
          */
         foreach ($this->bucket as $arrayIndex => $list) {
@@ -364,11 +366,15 @@ public function remove($key): bool {
          * is no node to remove.
          */
         if ($list->size() == 1 && $head->getKey() === $key) {
-            //$this->bucket[$arrayIndex] = null;
             unset($this->bucket[$arrayIndex]);
             return true;
         }
-        return $list->remove($key);
+        $removed = $list->remove($key);
+        echo $list->size();
+        echo "\n";
+//        $this->bucket[$arrayIndex] = $list;
+//        var_dump($this->bucket[$arrayIndex]);
+        return $removed;
     }
 
     /**
@@ -397,7 +403,7 @@ public function keySet(): array {
             $head = $list->getHead();
             while ($head !== null) {
                 $keySet[] = $head->getKey();
-                $head = $head->getNext();
+                $head     = $head->getNext();
             }
         }
         return $keySet;
@@ -407,7 +413,7 @@ public function keySet(): array {
      * @return array
      */
     public function countPerBucket() {
-        $i = 0;
+        $i     = 0;
         $array = [];
         /** @var SinglyLinkedList $list */
         foreach ($this->bucket as $list) {
@@ -421,15 +427,16 @@ public function countPerBucket() {
     /**
      * Specify data which should be serialized to JSON
      *
-     * @link http://php.net/manual/en/jsonserializable.jsonserialize.php
+     * @link  http://php.net/manual/en/jsonserializable.jsonserialize.php
      * @return mixed data which can be serialized by <b>json_encode</b>,
      * which is a value of any type other than a resource.
      * @since 5.4.0
      */
     public function jsonSerialize() {
         return [
-            "buckets" => $this->bucket
+            "buckets"    => $this->bucket
             , "max_size" => $this->maxSize,
         ];
     }
+
 }
diff --git a/tests/Lists/LinkedLists/SinglyLinkedListTest.php b/tests/Lists/LinkedLists/SinglyLinkedListTest.php
@@ -26,6 +26,7 @@
 
 namespace doganoo\PHPAlgorithmsTest\Lists\LinkedLists;
 
+use doganoo\PHPAlgorithms\Datastructure\Lists\LinkedLists\SinglyLinkedList;
 use doganoo\PHPAlgorithmsTest\Util\LinkedListUtil;
 use PHPUnit\Framework\TestCase;
 
@@ -72,4 +73,19 @@ public function testContains() {
         $this->assertTrue($list->containsKey("test") === true);
     }
 
+    public function testRemove() {
+        $singlyLinkedList = new SinglyLinkedList();
+        $singlyLinkedList->add("calorie_tracker", new class {
+
+        });
+        $singlyLinkedList->add("tnc", new class {
+
+        });
+
+        $this->assertTrue(2 === $singlyLinkedList->size());
+        $singlyLinkedList->remove("calorie_tracker");
+        $this->assertTrue(1 === $singlyLinkedList->size());
+
+    }
+
 }
diff --git a/tests/Table/HashTableTest.php b/tests/Table/HashTableTest.php
@@ -83,9 +83,25 @@ public function testGetNodeByValue() {
      * tests removing a value from the map
      */
     public function testRemove() {
-        $hashMap = HashTableUtil::getHashTable(500);
-        $boolean = $hashMap->remove(320);
-        $this->assertTrue($boolean);
+        $hashTable = new HashTable();
+        $hashTable->put("about", new class{});
+        $hashTable->put("account", new class{});
+        $hashTable->put("apps", new class{});
+        $hashTable->put("calorie_tracker", new class{});
+        $hashTable->put("tnc", new class{});
+        $hashTable->put("forgot_password", new class{});
+        $hashTable->put("general_api", new class{});
+        $hashTable->put("install", new class{});
+        $hashTable->put("login", new class{});
+        $hashTable->put("logout", new class{});
+        $hashTable->put("maintenance", new class{});
+        $hashTable->put("password_manager", new class{});
+        $hashTable->put("promotion", new class{});
+        $hashTable->put("register", new class{});
+        $hashTable->put("users", new class{});
+        $this->assertTrue(null !== $hashTable->get("calorie_tracker"));
+        $hashTable->remove("calorie_tracker");
+        $this->assertTrue(null === $hashTable->get("calorie_tracker"));
     }
 
     /**