From b67dd423cd43b056c19838144e39963d3ba02fb0 Mon Sep 17 00:00:00 2001
From: Oscar Najera <hi@oscarnajera.com>
Date: Thu, 6 Apr 2023 01:34:44 +0200
Subject: refactor, using collector

---
 AoC2022/07/solver.lisp | 71 +++++++++++++++++++++-----------------------------
 1 file changed, 30 insertions(+), 41 deletions(-)

(limited to 'AoC2022/07/solver.lisp')

diff --git a/AoC2022/07/solver.lisp b/AoC2022/07/solver.lisp
index a6c99ae..497b6f6 100644
--- a/AoC2022/07/solver.lisp
+++ b/AoC2022/07/solver.lisp
@@ -8,58 +8,47 @@
            (parse (item)
              (cond
                ((ppcre:register-groups-bind (dir) ("\\$ cd (\\w+|/)" item) (cons dir (scan))))
-               ((ppcre:register-groups-bind (size name) ("^(\\d+) (\\w+)" item)
-                  (cons name (parse-integer size)))))))
+               ((ppcre:register-groups-bind ((#'parse-integer size) name) ("^(\\d+) ([.\\w]+)" item)
+                  (cons name size))))))
     (car (scan))))
 
 (defun aggregate-size (tree)
-  (labels ((combiner (tri)
-             (list (car tri)
-                   (adder tri)
-                   (reduce (lambda (acc item)
-                             (if (numberp (cdr item)) ;; skips files
-                                 acc
-                                 (cons (combiner item) acc)))
-                           (cdr tri) :initial-value nil)))
-           (adder (tri)
-             (reduce (lambda (acc item)
-                       (+ acc (if (numberp (cdr item))
-                                  (cdr item)
-                                  (adder item))))
-                     (cdr tri) :initial-value 0)))
-    (combiner tree)))
-
-(defun flat-dir-size ()
-  (with-open-file (in "input")
-    (delete nil
-            (flatten-tree
-             (aggregate-size
-              (parse-to-tree in)))
-            :test #'eq) ))
-
-(defun flatten-tree (tree)
-  (cond
-    ((null tree) nil)
-    ((consp (car tree)) (nconc (flatten-tree (car tree))
-                               (flatten-tree (cdr tree))))
-    (t (cons (car tree) (flatten-tree (cdr tree))))))
+  (let (dir-list)
+    (labels ((combiner (tri)
+               (push (cons (car tri) (adder tri)) dir-list)
+               (mapc (lambda (item)
+                       (unless (numberp (cdr item)) ;; skips files
+                         (combiner item)))
+                     (cdr tri)))
+             (adder (tri)
+               (reduce (lambda (acc item)
+                         (+ acc (if (numberp (cdr item))
+                                    (cdr item)
+                                    (adder item))))
+                       (cdr tri) :initial-value 0)))
+      (combiner tree))
+    dir-list))
+
+(defun flat-dir-size (filename)
+  (with-open-file (in filename)
+    (aggregate-size
+     (parse-to-tree in))))
 
 (defun addr-small-dirs (dir-sizes small-limit)
-  (loop for (_name size) on dir-sizes by #'cddr
+  (loop for (_name . size) in dir-sizes
         when (< size small-limit)
           sum size))
 
 (defun dir-to-del (dir-sizes total-disk needed-disk)
-  (let* ((free-disk (- total-disk (cadr dir-sizes)))
+  (let* ((free-disk (- total-disk (cdar (last dir-sizes))))
          (to-free (- needed-disk free-disk)))
-    (loop for (_ size) on dir-sizes by #'cddr
+    (loop for (_name . size) in dir-sizes
           when (> size to-free)
             minimizing size)))
 
 (fiveam:test results
-             (fiveam:is (= 1845346
-                           (addr-small-dirs (flat-dir-size) 100000)))
-             (fiveam:is (= 3636703
-                           (dir-to-del (flat-dir-size) 70000000 30000000))))
-
-
+  (fiveam:is (= 95437 (addr-small-dirs (flat-dir-size "eg-in") 100000)))
+  (fiveam:is (= 1845346
+                (addr-small-dirs (flat-dir-size "input") 100000)))
+  (fiveam:is (= 3636703
+                (dir-to-del (flat-dir-size "input") 70000000 30000000))))
-- 
cgit v1.2.3