implement JS password scoring, td_stock approve logicc

lib/zxcvbn-php-master/src/Math/Impl/AbstractBinomialProvider.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ZxcvbnPhp\Math\Impl;
+
+use ZxcvbnPhp\Math\BinomialProvider;
+
+abstract class AbstractBinomialProvider implements BinomialProvider
+{
+    public function binom(int $n, int $k): float
+    {
+        if ($k < 0 || $n < 0) {
+            throw new \DomainException("n and k must be non-negative");
+        }
+
+        if ($k > $n) {
+            return 0;
+        }
+
+        // $k and $n - $k will always produce the same value, so use smaller of the two
+        $k = min($k, $n - $k);
+
+        return $this->calculate($n, $k);
+    }
+
+    abstract protected function calculate(int $n, int $k): float;
+}