fixup

1 files changed, 38 insertions, 0 deletions

diff --git a/coding-exercises/1/32.rkt b/coding-exercises/1/32.rkt
new file mode 100644
index 0000000..21a557c
--- /dev/null
+++ b/coding-exercises/1/32.rkt
@@ -0,0 +1,38 @@
+#lang racket
+
+(define (accumulate combiner null-value term a next b)
+  (define (iter a result)
+    (if (> a b)
+      result
+      (iter 
+        (next a)
+        (combiner
+          (term a)
+          result))))
+  (iter null-value a))
+
+(define (accumulate combiner null-value term a next b)
+  (if (> a b)
+    null-value
+    (combiner 
+      (term a)
+      (accumulate 
+        combiner 
+        null-value 
+        term (next a) next b)))) 
+
+
+(define (sum term a next b)
+  (accumulate
+    (lambda (x y) (+ x y))
+    0
+    term a next b))
+
+(define (product term a next b)
+  (accumulate
+    (lambda (x y) (* x y))
+    1
+    term a next b))
+
+(sum id 0 inc 8)
+(product id 1 inc 3)