solution to problem 002 in lisp

2016-10-19 11:33:42 -07:00 · 2016-10-19 11:33:42 -07:00 · 60b398489b
parent 57eb8dab59
commit 60b398489b
1 changed files with 11 additions and 0 deletions
--- a/lisp/euler002.lisp
+++ b/lisp/euler002.lisp
@ -0,0 +1,11 @@
+(load "euler.lisp")
+
+(defun fibonacci-list-helper (n builder)
+  (if (>= (+ (first builder) (first (rest builder))) n) builder (fibonacci-list-helper n (cons (+ (first builder) (first (rest builder))) builder)))
+)
+
+(defun fibonacci-list (n)
+  (fibonacci-list-helper n (list 2 1))
+)
+
+(defun solution () (sum (select (lambda (a) (eq (mod a 2) 0)) (fibonacci-list 4000000))))