Remove Nth Node From End Of List

LinkedList/ListNode.php

@@ -4,6 +4,7 @@
 
 /**
  * @covers \Hakam\LeetCodePhp\LinkedList\ListNode
+ * @codeCoverageIgnore
  */
 class ListNode
 {
@@ -13,7 +14,7 @@ class ListNode
     /**
      * @param int $val
      * @param null $next
-     * @codeCoverageIgnore
+
      */
     public function __construct($val = 0, $next = null)
     {

LinkedList/RemoveNthNodeFromEndOfList.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace Hakam\LeetCodePhp\LinkedList;
+
+class RemoveNthNodeFromEndOfList
+{
+    /**
+     * @param ListNode $head
+     * @param Integer $n
+     * @return ListNode
+     */
+  public  function removeNthFromEnd(ListNode $head, int $n) : ?ListNode
+    {
+        $dummy = new ListNode(0);
+        $dummy->next = $head;
+        $copyHead = $head;
+        $length = 0;
+        while ($copyHead !== null) {
+            $copyHead = $copyHead->next;
+            ++$length;
+        }
+        $length -= $n;
+        $copyHead = $dummy;
+        while ($length > 0) {
+            $length--;
+            $copyHead = $copyHead->next;
+        }
+
+        $copyHead->next = $copyHead->next->next;
+
+        return $dummy->next;
+    }
+}

Tests/Helper/InputFiles/RemoveNthNodeFromEndOfListTest.json

@@ -0,0 +1,14 @@
+{
+  "testCase1": {
+    "expectedResult":[2],
+    "input": [[1,2],2]
+  },
+  "testCase2": {
+    "expectedResult":[1,2,3,5],
+    "input": [[1,2,3,4,5],2]
+  },
+  "testCase3": {
+    "expectedResult":[],
+    "input": [[1],1]
+  }
+}

Tests/LinkedList/RemoveNthNodeFromEndOfListTest.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace Hakam\LeetCodePhp\Tests\LinkedList;
+
+
+use Hakam\LeetCodePhp\LinkedList\RemoveNthNodeFromEndOfList;
+use Hakam\LeetCodePhp\Tests\Helper\LinkedListHelperTrait;
+use Hakam\LeetCodePhp\Tests\Helper\MainTest;
+
+/**
+ * @covers \Hakam\LeetCodePhp\LinkedList\RemoveNthNodeFromEndOfList
+ */
+class RemoveNthNodeFromEndOfListTest extends MainTest
+{
+    use LinkedListHelperTrait;
+
+    /**
+     * @dataProvider provideData
+     */
+    public function testWithDataList($expectedResult, $inputData): void
+    {
+        $list = $this->convertFromArray($inputData[0]);
+        $remover = new RemoveNthNodeFromEndOfList();
+        self::assertEmpty(array_diff($expectedResult,
+            $this->convertToArray(
+                $remover->removeNthFromEnd($list,$inputData[1]))
+        ));
+    }
+}