day 7: idk

7.rkt

@@ -27,25 +27,19 @@
        (ft-add-file! file-tree (reverse cwd) file size)
        cwd]))
 
-  (define sizes (make-hash))
+  (define sizes '())
 
-  (define (ft-lookup ft path)
-    (match path
-      ['() ft]
-      [(cons fst rst) (ft-lookup (hash-ref ft fst) rst)]))
-
-  (define (record-size! ft path)
+  (define (record-size! ft)
     (define size
-      (for/sum ([(k v) (in-hash (ft-lookup ft path))])
+      (for/sum ([(k v) (in-hash ft)])
         (if (number? v)
           v
-          (record-size! ft (append path (list k))))))
-    (hash-set! sizes path size)
+          (record-size! v))))
+    (set! sizes (cons size sizes))
     size)
 
-  (record-size! file-tree '())
-
-  (sort (hash-values sizes) <))
+  (record-size! file-tree)
+  (sort sizes <))
 
 (define (part1 input)
   (define *at-most* 100000)