From fd5e846f2fa8a29d9a000428c348926d70ba381d Mon Sep 17 00:00:00 2001
From: Pekka Laiho <pekka.i.laiho@gmail.com>
Date: Sat, 6 Jun 2020 15:59:05 +0700
Subject: [PATCH] Fibonacci numbers

---
 mad/fib.mad | 11 +++++++++++
 1 file changed, 11 insertions(+)
 create mode 100644 mad/fib.mad

diff --git a/mad/fib.mad b/mad/fib.mad
new file mode 100644
index 0000000..61eb631
--- /dev/null
+++ b/mad/fib.mad
@@ -0,0 +1,11 @@
+; Functions to calculate Fibonacci numbers
+
+; Slow recursive version
+(def slowFib (fn (n) (if (< n 2) n (+ (slowFib (- n 1)) (slowFib (- n 2))))))
+
+; Return the sum of the last 2 numbers in a sequence
+(def sumOfLast (fn (l) (+ (last l) (get l (- (len l) 2)))))
+
+; Faster version, return vector of n numbers
+(def fibListRec (fn (n l) (if (< (len l) n) (fibListRec n (push l (sumOfLast l))) l)))
+(def fibList (fn (n) (fibListRec n [0 1])))