name directories like the realm repo.

1 files changed, 21 insertions, 0 deletions

diff --git a/chapter2/guess.rkt b/chapter2/guess.rkt
new file mode 100644
index 0000000..ab05056
--- /dev/null
+++ b/chapter2/guess.rkt
@@ -0,0 +1,21 @@
+#lang racket
+
+(define lower 1)
+
+(define upper 100)
+
+(define (start n m)
+  (set! lower (min n m))
+  (set! upper (max n m))
+  (guess))
+
+(define (guess)
+  (quotient (+ lower upper) 2))
+
+(define (smaller)
+  (set! upper (max lower (sub1 (guess))))
+  (guess))
+
+(define (bigger)
+  (set! lower (min upper (add1 (guess))))
+  (guess))