Bidirectional bubble sort

Author: lerabela

Sorting/Bubble Sort/bidirectional_bubble_sort.php

@@ -0,0 +1,75 @@
+<?php
+
+$unsorted = array(79,13,53,11,94,39,4,28,3,80);
+
+/**
+ * Swap function using a list asignment
+ * @param $arr array 
+ * @param $idx1 int
+ * @param $idx2 int
+ */
+function swap(array &$arr, int $idx1, int $idx2){
+
+    /**
+     * Use list to assign values from a given array
+     */
+    list($arr[$idx1], $arr[$idx2]) = array($arr[$idx2],$arr[$idx1]);
+
+}
+
+/**
+ * Bidirecctional Bubble Sort
+ * TODO: implement using threads
+ */
+function bi_bubble_sort(array &$unsorted) : array{
+
+    $swap = true;
+    $array_count = count($unsorted) - 1;
+
+    do{
+
+        $swap = false;
+
+        // sort left directional
+        for($idx = 0; $idx <= $array_count; $idx++){
+
+            $comp = $idx + 1;
+            if(isset($unsorted[$comp]) && $unsorted[$idx] > $unsorted[$comp]){
+                swap($unsorted,$idx, $comp);
+                $swap = true;
+                echo "swap left \n";
+            }
+
+        }
+
+        // break if no sort
+        if($swap == false){
+            break;
+        }
+
+        // Sort right directional
+        for($idx = $array_count; $idx >= 0; $idx--){
+
+            $comp = $idx - 1;
+            if(isset($unsorted[$comp]) && $unsorted[$idx] < $unsorted[$comp]){
+                swap($unsorted, $idx, $comp);
+                $swap = true;
+                echo "swap right \n";
+            }
+
+        }
+
+    }while($swap);
+
+    // return array
+    return $unsorted;
+
+}
+
+// print results
+echo "\n";
+$sorted = bi_bubble_sort($unsorted);
+foreach($sorted as $val){
+    echo $val, " ";
+}
+echo "\n";