From c5ed81d85e2c131df3112a5a02d7946786d5c190 Mon Sep 17 00:00:00 2001
From: m-maksyutin <m.maksyutin@gmail.com>
Date: Thu, 28 Jun 2018 21:03:31 +0300
Subject: [PATCH] Add recursive factorial function (#85)

* Fix LinkedList

* Fix the prepend method for the LinkedList

* Fix the remove method for the MinHeap

* Correct a comment

* Fix BST removal method

* Fix the findEdge method of the graph

* Fix the value returned by DisjointSet union

* Add recursive factorial function
---
 .../factorial/__test__/factorialRecursive.test.js     | 11 +++++++++++
 src/algorithms/math/factorial/factorialRecursive.js   |  7 +++++++
 2 files changed, 18 insertions(+)
 create mode 100644 src/algorithms/math/factorial/__test__/factorialRecursive.test.js
 create mode 100644 src/algorithms/math/factorial/factorialRecursive.js

diff --git a/src/algorithms/math/factorial/__test__/factorialRecursive.test.js b/src/algorithms/math/factorial/__test__/factorialRecursive.test.js
new file mode 100644
index 00000000..9029faee
--- /dev/null
+++ b/src/algorithms/math/factorial/__test__/factorialRecursive.test.js
@@ -0,0 +1,11 @@
+import factorialRecursive from '../factorialRecursive';
+
+describe('factorialRecursive', () => {
+  it('should calculate factorial', () => {
+    expect(factorialRecursive(0)).toBe(1);
+    expect(factorialRecursive(1)).toBe(1);
+    expect(factorialRecursive(5)).toBe(120);
+    expect(factorialRecursive(8)).toBe(40320);
+    expect(factorialRecursive(10)).toBe(3628800);
+  });
+});
diff --git a/src/algorithms/math/factorial/factorialRecursive.js b/src/algorithms/math/factorial/factorialRecursive.js
new file mode 100644
index 00000000..e2b4aec6
--- /dev/null
+++ b/src/algorithms/math/factorial/factorialRecursive.js
@@ -0,0 +1,7 @@
+/**
+ * @param {number} number
+ * @return {number}
+ */
+export default function factorialRecursive(number) {
+  return number > 1 ? number * factorialRecursive(number - 1) : 1;
+}