Day 4 - common lisp

README.md

@@ -8,7 +8,8 @@
   - [Day 1](./day-1)
 - [x] Clojure
   - [Day 2](./day-2)
-- [] Common LISP
+- [x] Common LISP
+  - [Day 3](./day-3)
 - [] C++
 - [] Dart
 - [] Elixir

day-03/sol.lisp

@@ -0,0 +1,33 @@
+(ql:quickload "cl-ppcre")
+
+(defun get-ranges (line)
+  (ppcre:register-groups-bind ((#'parse-integer first second third fourth))
+      ("(\\d+)-(\\d+),(\\d+)-(\\d+)" line :sharedp t)
+    `((,first ,second) (,third ,fourth))))
+
+(defun ranges-may-subset-of-one (a b)
+  (member-if
+   (lambda (r)
+     (and
+      (>= (caar r) (caadr r))
+      (<= (cadar r) (cadadr r))))
+   `((,a ,b) (,b ,a))))
+
+(defun range-is-contained-at-all (a b)
+  (and
+   (<= (car a) (cadr b))
+   (>= (cadr a) (car b))))
+
+(defun main ()
+  (let ((lines (uiop:read-file-lines "input")))    
+    (print
+     (mapcar (lambda (f)
+               (reduce (lambda (a x)
+                         (if (apply f (get-ranges x))
+                             (1+ a)
+                             a))
+                       lines
+                       :initial-value 0))
+             '(range-is-contained range-may-be-subset-of-one)))))
+
+(main)