Median Stream

Author: RamyHakam

Heap/MedianStream.php

@@ -0,0 +1,51 @@
+<?php
+
+namespace Hakam\LeetCodePhp\Heap;
+
+use SplMinHeap;
+
+class MedianStream
+{
+    public function findMedian($arr): array
+    {
+        for ($key = 1, $keyMax = count($arr); $key <= $keyMax; $key++) {
+            $minHeap = new SplMinHeap();
+
+            for ($index = 0; $index < $key; $index++) {
+
+                $minHeap->insert($arr[$index]);
+            }
+
+            if ($key === 1) {
+                $temp = $minHeap->extract();
+                $maiden [] = $temp;
+                continue;
+            }
+
+            if ($key === 2) {
+                $temp = floor(($minHeap->extract() + $minHeap->extract()) / 2);
+                $maiden [] = $temp;
+                continue;
+            }
+
+            if ($key % 2 === 0) {
+                for ($i = 0; $i < ($key / 2) - 1; $i++) {
+                    $minHeap->extract();
+                }
+                $temp = floor(($minHeap->extract() + $minHeap->extract()) / 2);
+            } else {
+
+                for ($i = 0; $i < floor($key / 2); $i++) {
+                    $minHeap->extract();
+                }
+
+                $temp = $minHeap->extract();
+
+            }
+
+            $maiden [] = $temp;
+
+        }
+        return $maiden;
+    }
+}

Tests/Heap/MedianStreamTest.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace Hakam\LeetCodePhp\Tests\Heap;
+
+use Hakam\LeetCodePhp\Heap\MedianStream;
+use Hakam\LeetCodePhp\Tests\Helper\MainTest;
+
+class MedianStreamTest extends MainTest
+{
+    /**
+     * @dataProvider provideData
+     */
+    public function testWithDataList($expectedResult, $inputData): void
+    {
+       $medianStream = new MedianStream();
+       self::assertEmpty(array_diff($expectedResult,$medianStream->findMedian($inputData)));
+    }
+}

Tests/Helper/InputFiles/MedianStreamTest.json

@@ -0,0 +1,10 @@
+{
+  "testCase1": {
+    "expectedResult": [5, 10, 5, 4],
+    "input":  [5, 15, 1, 3]
+  },
+  "testCase2": {
+    "expectedResult": [1,1],
+    "input": [1,2]
+  }
+}