From a13cc209e002a72a18c659d22ed39dbd99be2fcd Mon Sep 17 00:00:00 2001
From: Charles Cabergs <me@cacharle.xyz>
Date: Mon, 26 Jul 2021 18:15:52 +0200
Subject: problem 1 2 in clojure

---
 clojure/002-even_fibonacci_numbers.clj | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 clojure/002-even_fibonacci_numbers.clj

(limited to 'clojure/002-even_fibonacci_numbers.clj')

diff --git a/clojure/002-even_fibonacci_numbers.clj b/clojure/002-even_fibonacci_numbers.clj
new file mode 100644
index 0000000..092f23c
--- /dev/null
+++ b/clojure/002-even_fibonacci_numbers.clj
@@ -0,0 +1,29 @@
+;;;;
+;; Even Fibonacci numbers
+;; Problem 2
+;;
+;; Each new term in the Fibonacci sequence is generated by adding the previous two terms. By
+;; starting with 1 and 2, the first 10 terms will be:
+;; 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
+;; By considering the terms in the Fibonacci sequence whose values do not exceed four
+;; million, find the sum of the even-valued terms.
+;;;;
+
+(def fib
+  (memoize (fn [n]
+             (case n
+               0 1
+               1 1
+               (+' (fib (-' n 1)) (fib (-' n 2)))))))
+
+(def +top+ 4000000)
+
+(def result
+  (reduce +
+    (for [x (range 1 1000)
+          :let [f (fib x)]
+          :when (= (mod f 2) 0)
+          :while (< f +top+)]
+      f)))
+
+(println result)
-- 
cgit