second task of day 1, cool

day1.lisp

@@ -63,3 +63,63 @@ my-int
 
       ;; (in "day1-input.txt")
 (calc-max-inventory-calories  "day1-input.txt")
+
+;;; and second task - find TOP 3 inventory sums, and what is their total
+;; how'd i do that?
+;; would be cool to do a class, that would be able to store the top 3
+;; and would have single method to check and possibly include a new number with eviction of the lovest number
+;; do I go for CLOS here?
+;; ugh.
+
+(setq my-prev-max (list 1 4 5 7))
+(apply #'min my-prev-max)
+(set-difference my-prev-max (list 1))
+my-prev-max
+(set-difference my-prev-max (list  (apply #'min my-prev-max)))
+
+;; so, i could use that on the "found max"
+;; could also store "cur minmal maximul"
+
+(defun calc-3-max-inventory-calories (filename)
+  (setq current-sum 0)
+  (setq current-3-max '())
+  (with-open-file
+      (in filename)
+    (loop
+      for line = (read-line in nil nil)
+      while line
+      if (string-equal line "")
+        do (progn
+             ;; current inventory ended,
+             ;; check whether it's new max and null accum
+             (setq current-3-max (cons current-sum current-3-max))
+             (if (< 3 (length current-3-max))
+                 (setq current-3-max
+                       (set-difference current-3-max (list  (apply #'min current-3-max))))
+                 )
+             (setq current-sum 0))
+      else do (setq current-sum (+ current-sum (parse-integer line)))
+      ))
+  (apply #'+ current-3-max))
+
+(append (list 12 1 14) 15)
+(setq my-prepend (cons 15 (list 12 1 14)))
+(apply #'+ (list 1 2 3))
+
+(calc-3-max-inventory-calories  "day1-input.txt")
+
+current-3-max
+(> 3 2)
+
+;; ok. so notes for today:
+;; 1. i'm messing up (> 3 1) in conditions
+;; 2. I really should start using #'LET instead of #'SETQ
+;; SETQ are for defining what? global names? these are set and available outside of the function
+;; even though i didn't create them as DEFVAR? Or maybe I did, for the first function
+;; ok then
+;; 3. looking in Common Lisp Cookbook : https://lispcookbook.github.io/cl-cookbook/iteration.html
+;; for the examples of the loops and set operations
+;; and another tutorial with sample of reading the file https://riptutorial.com/common-lisp/example/10284/reading-file
+;; and https://www.tutorialspoint.com/lisp/lisp_file_io.htm
+;; and https://stackoverflow.com/questions/44466001/read-from-file-common-lisp
+;; 4. Sad that I don't really look into the efficient ways of doing things