From cac67889459e954376b5cdcb69f16445c293ea7b Mon Sep 17 00:00:00 2001
From: Moony <moony@tcp.direct>
Date: Wed, 7 Jul 2021 19:38:33 -0700
Subject: [PATCH] Initial commit.

---
 fib_challenge.py | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 fib_challenge.py

diff --git a/fib_challenge.py b/fib_challenge.py
new file mode 100644
index 0000000..b93f794
--- /dev/null
+++ b/fib_challenge.py
@@ -0,0 +1,23 @@
+#!/usr/bin/env python3
+
+
+def fib(n):
+    if n >= 0:
+        return fibiter(1, 0, 0, 1, n)
+    if n < 0:
+        a, b = 0, 1
+        for _ in range(0, n, -1):
+            a, b = b - a, a
+        return a
+
+
+def fibiter(a, b, p, q, count):
+    if count == 0:
+        return b
+    if count % 2 == 0:
+        return fibiter(a, b, p * p + q * q, q * q + 2 * p * q, count / 2)
+    else:
+        return fibiter(b * q + a * q + a * p, b * p + a * q, p, q, count - 1)
+
+
+print(fib(1000000))