*

1 files changed, 22 insertions, 0 deletions

diff --git a/js/games/nluqo.github.io/~bh/61a-pages/Lectures/3.5/prime1.scm b/js/games/nluqo.github.io/~bh/61a-pages/Lectures/3.5/prime1.scm
new file mode 100644
index 0000000..35f7a70
--- /dev/null
+++ b/js/games/nluqo.github.io/~bh/61a-pages/Lectures/3.5/prime1.scm
@@ -0,0 +1,22 @@
+
+
+(define (prime? n)
+  (null? (filter (lambda (x) (= (remainder n x) 0))
+                 (range 2 (- n 1)))))
+
+(define (range from to)
+  (if (> from to)
+      '()
+      (cons from (range (+ from 1) to))))
+
+
+(define (filter predicate data)
+  (cond ((null? data) '())
+        ((predicate (car data))
+         (cons (car data) (filter predicate (cdr data))))
+        (else (filter predicate (cdr data)))))
+
+
+
+
+;; try (filter prime? (range 2 100))