From 77445e8fbe89e6512152c8df401124a8eaf97fff Mon Sep 17 00:00:00 2001
From: Caleb Webber <caleb@codingthemsoftly.com>
Date: Fri, 28 Feb 2025 01:53:34 -0500
Subject: [PATCH] add solution to problem 20

---
 problems/20/solution.exs | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
 create mode 100644 problems/20/solution.exs

diff --git a/problems/20/solution.exs b/problems/20/solution.exs
new file mode 100644
index 0000000..ee20686
--- /dev/null
+++ b/problems/20/solution.exs
@@ -0,0 +1,15 @@
+defmodule FactDigitSum do
+  defp fact(1, acc), do: acc
+  defp fact(n, acc), do: fact(n - 1, n * acc)
+  def fact(n), do: fact(n - 1, n)
+
+  defp digit_sum(0, acc), do: acc
+  defp digit_sum(n, acc), do: digit_sum(div(n, 10), rem(n, 10) + acc)
+  def digit_sum(n), do: digit_sum(n, 0)
+end
+
+
+FactDigitSum.fact(100)
+|> FactDigitSum.digit_sum()
+|> IO.puts()
+