From 84ed7dbc7fb20d2646f6783b4ed91a8e653092eb Mon Sep 17 00:00:00 2001
From: David Kerkeslager <kerkeslager@gmail.com>
Date: Tue, 13 Dec 2016 10:04:45 -0500
Subject: [PATCH] Solved project euler 3

---
 ...cci.exs => 0002-sum-of-even-fibonacci.exs} |  0
 euler/elixir/0003-largest-prime-factor.exs    | 25 +++++++++++++++++++
 2 files changed, 25 insertions(+)
 rename euler/elixir/{0002-sum-of-fibonacci.exs => 0002-sum-of-even-fibonacci.exs} (100%)
 create mode 100644 euler/elixir/0003-largest-prime-factor.exs

diff --git a/euler/elixir/0002-sum-of-fibonacci.exs b/euler/elixir/0002-sum-of-even-fibonacci.exs
similarity index 100%
rename from euler/elixir/0002-sum-of-fibonacci.exs
rename to euler/elixir/0002-sum-of-even-fibonacci.exs
diff --git a/euler/elixir/0003-largest-prime-factor.exs b/euler/elixir/0003-largest-prime-factor.exs
new file mode 100644
index 0000000..79e7676
--- /dev/null
+++ b/euler/elixir/0003-largest-prime-factor.exs
@@ -0,0 +1,25 @@
+defmodule LargestPrimeFactor do
+  def largest_prime_factor(start, n) do
+    if start >= (n / 2) do
+      n
+    else
+      if rem(n, start) == 0 do
+        largest_prime_factor(start, div(n, start))
+      else
+        largest_prime_factor(start + 2, n)
+      end
+    end
+  end
+      
+  def largest_prime_factor(n) do
+    n_next = if rem(n, 2) == 0 do
+      div(n, 2)
+    else
+      n
+    end
+
+    largest_prime_factor(3, n_next)
+  end
+end
+
+IO.puts(LargestPrimeFactor.largest_prime_factor(600851475143))
-- 
2.20.1