day 1

1 files changed, 30 insertions, 0 deletions

diff --git a/01/2.scm b/01/2.scm
new file mode 100644
index 0000000..e9426cb
--- /dev/null
+++ b/01/2.scm
@@ -0,0 +1,30 @@
+(import (chicken string))
+(import (chicken io))
+(import (chicken sort))
+(import srfi-1)
+
+(define input
+  (with-input-from-file "input"
+    (lambda ()
+      (let loop ((ret '()))
+        (let ((line (read-line)))
+          (if (eof-object? line)
+              (reverse ret)
+              (loop (cons line ret))))))))
+
+(set! input (map string-split input))
+
+(define first-lst (map string->number (map car input)))
+(define second-lst (map string->number (map cadr input)))
+
+(set! first-lst (sort first-lst <))
+(set! second-lst (sort second-lst <))
+
+(define (times x)
+  (length (filter (lambda (a) (= a x))
+                  second-lst)))
+
+(define times-lst (map times first-lst))
+
+(display (apply + (map * first-lst times-lst)))
+(newline)