From 9434ab9dc92eb3f79726ffa44b89fde1e7cbe47e Mon Sep 17 00:00:00 2001
From: Sahil Afrid Farookhi <msafarookhi@gmail.com>
Date: Wed, 28 Apr 2021 14:56:40 +0530
Subject: [PATCH] factorial non-recursive non-iterative feature implementation

---
 DIRECTORY.md                                  |  1 +
 .../factorial_non_recursive_non_iterative.rb  | 44 +++++++++++++++++++
 2 files changed, 45 insertions(+)
 create mode 100644 maths/factorial_non_recursive_non_iterative.rb

diff --git a/DIRECTORY.md b/DIRECTORY.md
index a110ecb..fa2aaf9 100644
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@@ -53,6 +53,7 @@
   * [Ceil](https://github.com/TheAlgorithms/Ruby/blob/master/maths/ceil.rb)
   * [Ceil Test](https://github.com/TheAlgorithms/Ruby/blob/master/maths/ceil_test.rb)
   * [Decimal To Binary](https://github.com/TheAlgorithms/Ruby/blob/master/maths/decimal_to_binary.rb)
+  * [Factorial Non-recursive and Non-iterative](https://github.com/TheAlgorithms/Ruby/blob/master/maths/factorial_non_recursive_non_iterative.rb)
   * [Fibonacci](https://github.com/TheAlgorithms/Ruby/blob/master/maths/fibonacci.rb)
   * [Find Max](https://github.com/TheAlgorithms/Ruby/blob/master/maths/find_max.rb)
   * [Find Min](https://github.com/TheAlgorithms/Ruby/blob/master/maths/find_min.rb)
diff --git a/maths/factorial_non_recursive_non_iterative.rb b/maths/factorial_non_recursive_non_iterative.rb
new file mode 100644
index 0000000..17a4f77
--- /dev/null
+++ b/maths/factorial_non_recursive_non_iterative.rb
@@ -0,0 +1,44 @@
+# A ruby program to find factorial of a given integer
+# Factorial of a given integer is defined as the product of all the positive integers less than or equal to the given integer
+# Mathematical representation: n! = n * (n - 1) * (n - 2) * ... * 1
+
+#
+# Non-recursive approach
+#
+
+def factorial(number)
+  if number < 0
+    "Please check your input number! The given number is a negative number."
+  else
+    if number == 0
+      "The factorial of #{number} is 1."
+    else
+      "The factorial of #{number} is #{(1..number).inject(:*)}."
+    end
+  end
+  rescue
+    "Error: Please provide integer only!"
+end
+
+# Valid inputs
+puts factorial(0)
+# The factorial of 0 is 1.
+
+puts factorial(4)
+# The factorial of 4 is 24.
+
+puts factorial(10)
+# The factorial of 10 is 3628800.
+
+puts factorial(1)
+# The factorial of 1 is 1.
+
+puts factorial(-5)
+# Please check your input number! The given number is a negative number.
+
+# Invalid inputs
+puts factorial("a")
+# Error: Please provide integer only!
+
+puts factorial("2")
+# Error: Please provide integer only!