Current Status

As of this post I only did Day 1, 2, and 3. The current day for this is Day 6. I been doing this at my own pace. I feel like I’m getting better with lisp with these puzzles, and I had to look at other people’s solutions to fully understand what the problem was asking for.

Day 3

Day 3 has you finding out how many trees you hit on a toboggan stuck on one path here is the code (defparameter toboggan-vel ‘((1 1) (3 1) (5 1) (7 1) (1 2))) (defun read-file-in (filename) (with-open-file ( in filename :if-does-not-exist nil :external-format ‘(:utf-8 :replacement “?”)) (loop for line = ( read-line in nil nil ) while line collect line))) (defun is-tree? (pos-char) (if (char= pos-char ##) t)) (defun toboggan-y-vel (lines vel) (cond ((eq lines nil) ‘()) ((= vel 0) lines) (t (toboggan-y-vel (cdr lines) (- vel 1))))) (defun check-toboggan-path (lines pos) (cond ((eq lines nil) ‘()) ((not (is-tree? (char (subseq (car lines) pos (+ pos 1)) 0))) (cons #\O (check-toboggan-path (cdr lines) (mod (+ pos toboggan-x-vel) (length (car lines)))))) ((is-tree? (char (subseq (car lines) pos (+ pos 1)) 0)) (cons #\X (check-toboggan-path (cdr lines) (mod (+ pos toboggan-x-vel) (length (car lines)))))) (t ‘()))) (defun check-toboggan-path-2 (lines pos y-vel x-vel) (cond ((eq lines nil) ‘()) ((not (is-tree? (char (subseq (car lines) pos (+ pos 1)) 0))) (cons #\O (check-toboggan-path-2 (toboggan-y-vel lines y-vel) (mod (+ pos x-vel) (length (car lines))) y-vel x-vel))) ((is-tree? (char (subseq (car lines) pos (+ pos 1)) 0)) (cons #\X (check-toboggan-path-2 (toboggan-y-vel lines y-vel) (mod (+ pos x-vel) (length (car lines))) y-vel x-vel))) (t ‘()))) (defun count-tree-hits (path) (loop for item in path when (char= item #\X) sum 1 into total finally (return total))) (defun mul-tree-hit-counts (tree-hit-list) (cond ((eq tree-hit-list nil) 1) (t (* (car tree-hit-list) (mul-tree-hit-counts (cdr tree-hit-list)))))) (defun loop-vel () (loop for item in toboggan-vel collect (count-tree-hits (check-toboggan-path-2 (read-file-in “puz3.in”) 0 (cadr item) (car item)))))

Advent of Code

I figure I would give it a try this year. Just some small problems to code out. I the language I chose to use was Common Lisp using sbcl. As of this post I just did Day 1 and Day 2. I’m using common lisp because I though it be fun to use and I still want to get better at using it. I still had to search around to find out how to use some of the functions in lisp still, but I feel I like I’m getting there.

Day 1

Day 1 was to find what 2 transactions summed equal to 2020 and give the product of those numbers (defparameter transactions nil) (defun read-file-in (filename) (with-open-file ( in filename :if-does-not-exist nil :external-format ‘(:utf-8 :replacement “?”)) (loop for line = ( read-line in nil nil ) while line collect line))) ;;part one (defun sum-2020? (transaction) (loop for item in transactions when (= (+ transaction item) 2020) return (* transaction item))) ;;part two (defun sum-three-2020? (transaction) (loop for item2 in transactions collect (loop for item3 in transactions when (= (+ transaction item2 item3) 2020) return (* transaction item2 item3))))

Day 2

Day 2’s was validating password rules from a database corruption. For this one I borrows a snippet from common lisp cookbook and rolled my own boolean-xor (defparameter password-policy nil) (defun read-file-in (filename) (with-open-file ( in filename :if-does-not-exist nil :external-format ‘(:utf-8 :replacement “?”)) (loop for line = ( read-line in nil nil ) while line collect line))) ;;took from http://cl-cookbook.sourceforge.net/strings.html (defun split-by-one-space (string) “Returns a list of substrings of string divided by ONE space each. Note: Two consecutive spaces will be seen as if there were an empty string between them.” (loop for i = 0 then (1+ j) as j = (position #\Space string :start i) collect (subseq string i j) while j)) (defun split-by-one-hypen (string) “returns a list of substrings of string divided by ONE hypen” (loop for i = 0 then (1+ j) as j = (position #- string :start i) collect (subseq string i j) while j)) (defun process-file-line (line) (list (car (split-by-one-hypen (car (split-by-one-space line)))) (car (cdr (split-by-one-hypen (car (split-by-one-space line))))) (subseq (car (cdr (split-by-one-space line))) 0 1) (car (cddr (split-by-one-space line))))) (defun boolean-xor ( test1 test2 ) (cond ((and test1 test2) nil) ((or test1 test2) t) (t nil))) (defun valid-password? (password) (if (<= (parse-integer (car password)) (count (char (caddr password) 0) (cadddr password) :test #‘equal) (parse-integer (cadr password))) t)) (defun valid-password2? (password) (if (boolean-xor (char= (char (caddr password) 0) (char (cadddr password) (- (parse-integer (car password)) 1))) (char= (char (caddr password) 0) (char (cadddr password) (- (parse-integer (cadr password)) 1)))) t)) (defun count-valid-passwords (pass-list) (loop for item in pass-list when item sum 1 into total finally (princ total)))

Update

So I updated this blog again to use flask and python. I figure if I did this way it can open up a few more things I can do for the blog. I looked into webmentions and it looked hard to do under hugo so I figure I would just update to use a server side blog.

Any weirdness

Let me know if anything weird happens on this site on my mastodon account or whatever works for you