Counting sort with PHP tested with PHPunit

mitogh · mitogh · commit e4e2c6334d2c · 2014-01-11T20:13:22.000-06:00
diff --git a/Counting_Sort/PHP/mitogh/counting_sort.php b/Counting_Sort/PHP/mitogh/counting_sort.php
@@ -0,0 +1,35 @@
+<?php
+/**
+ * Counting Sort Algirithm 
+ *
+ * @param   Array   $array  The original array
+ * @return  Array   $order  The order array
+ */
+function counting_sort($array = []){
+    // Return [] if the array has no elements
+    if( !is_array($array) || !count($array) ){
+        return $array;
+    }
+    
+    // Find the min and max value
+    $max = max($array);
+    $min = min($array);
+    
+    // Fill the aux array from min to max with 0
+    $aux = [];
+    $aux = array_fill($min, $max, 0);
+
+    foreach($array as $element){
+        $aux[$element]++;
+    }
+
+    // Fill the order array
+    $order = [];
+    foreach($aux as $key => $value){
+        $i = 0; 
+        while($i++ < $value){
+            array_push($order, $key);
+        }
+    }
+    return $order;
+}
diff --git a/Counting_Sort/PHP/mitogh/counting_sort_test.php b/Counting_Sort/PHP/mitogh/counting_sort_test.php
@@ -0,0 +1,31 @@
+<?php 
+
+require 'counting_sort.php'; 
+
+class CountingSortTest extends PHPUnit_Framework_TestCase{
+
+    public function testNoParameters(){
+        $this->assertEmpty(counting_sort([]));
+    }
+
+    public function testArrayWithUnorderElements(){
+        $original = [3,5,7,1,5,1,2,3,2,71,2,3,4,71,47,7];
+        $copy = [3,5,7,1,5,1,2,3,2,71,2,3,4,71,47,7];
+        sort($copy, SORT_NUMERIC);
+
+        $this->assertEquals(counting_sort($original), $copy);
+    } 
+    
+    public function testArrayWithOrderelements(){
+        $original = [0,1,2,3,4,5,6,7,8,9,10];
+        $copy = [0,1,2,3,4,5,6,7,8,9,10];
+        
+        $this->assertEquals(counting_sort($original), $copy);
+    } 
+
+    public function testArrayWithRepeatedElements(){
+        $original = [1,1,1,1,1,1,1,1,1,1,1];
+        $copy = [1,1,1,1,1,1,1,1,1,1,1];
+        $this->assertEquals(counting_sort($original), $copy);
+    }
+}
