Initial data commit

Task/Sorting-algorithms-Patience-sort/PHP/sorting-algorithms-patience-sort.php

@@ -0,0 +1,43 @@
+<?php
+class PilesHeap extends SplMinHeap {
+    public function compare($pile1, $pile2) {
+        return parent::compare($pile1->top(), $pile2->top());
+    }
+}
+
+function patience_sort(&$n) {
+    $piles = array();
+    // sort into piles
+    foreach ($n as $x) {
+        // binary search
+        $low = 0; $high = count($piles)-1;
+        while ($low <= $high) {
+            $mid = (int)(($low + $high) / 2);
+            if ($piles[$mid]->top() >= $x)
+                $high = $mid - 1;
+            else
+                $low = $mid + 1;
+        }
+        $i = $low;
+        if ($i == count($piles))
+            $piles[] = new SplStack();
+        $piles[$i]->push($x);
+    }
+
+    // priority queue allows us to merge piles efficiently
+    $heap = new PilesHeap();
+    foreach ($piles as $pile)
+        $heap->insert($pile);
+    for ($c = 0; $c < count($n); $c++) {
+        $smallPile = $heap->extract();
+        $n[$c] = $smallPile->pop();
+        if (!$smallPile->isEmpty())
+        $heap->insert($smallPile);
+    }
+    assert($heap->isEmpty());
+}
+
+$a = array(4, 65, 2, -31, 0, 99, 83, 782, 1);
+patience_sort($a);
+print_r($a);
+?>