Arnot

(defun aoc-day3-1 (input)
  (let ((num-correct-passphrases 0))
    (dolist (passphrase input)
      (let ((words (split-string passphrase " ")))
        (when (= (length words)
                 (length (delete-dups words)))
          (incf num-correct-passphrases))))
    num-correct-passphrases))

Arnot

;; The captcha requires you to review a sequence of digits (your puzzle input) and find the sum of
;; all digits that match the next digit in the list. The list is circular, so the digit after the
;; last digit is the first digit in the list.

(defun aoc-string-to-numbers (input)
  (mapcar (lambda (c) (- c ?0))
          (string-to-list input)))

(defun aoc-day1-1 (input)
  (let* ((in-list (aoc-string-to-numbers input))

Arnot

(defun ca-vectorize ()
  (let* ((line (thing-at-point 'line t))
         (ll (string-to-list line))
         (result (make-vector (1- (length ll)) 0))) ; skip newline
    (loop for c in ll
          for i below (length ll)
          do (unless (equal c ?\n)
               (if (equal c ?\s)
                   (setf (elt result i) 0)
                 (setf (elt result i) 1))))

Arnot

(defun ca-vectorize ()
  (let* ((line (thing-at-point 'line t))
         (ll (string-to-list line))
         (result (make-vector (1- (length ll)) 0))) ; skip newline
    (loop for c in ll
          for i below (length ll)
          do (unless (equal c ?\n)
               (if (equal c ?\s)
                   (setf (elt result i) 0)
                 (setf (elt result i) 1))))

Arnot

(defun ca-vectorize ()
  (let* ((line (thing-at-point 'line t))
         (ll (string-to-list line))
         (result (make-vector (1- (length ll)) 0))) ; skip newline
    (loop for c in ll
          for i below (length ll)
          do (unless (equal c ?\n)
               (if (equal c ?\s)
                   (setf (elt result i) 0)
                 (setf (elt result i) 1))))

Arnot

(defun catalan-next-row (v)
  (if (or (null v)
          (= (length v) 0))
      [1]
    (let ((r (make-vector (1+ (length v)) 1)))
      (dotimes (x (length v))
        (unless (= x 0)
          (setf (aref r x)
                (+ (aref v x)
                   (aref r (1- x))))))

Arnot

(defun my/move-to-middle ()
  (interactive)
  (let* ((begin (line-beginning-position))
         (end (line-end-position))
         (middle (+ begin (/ (- end begin) 2))))
    (goto-char middle)))

(global-set-key (kbd "C-c m") 'my/move-to-middle)

Arnot

;; -*- mode: emacs-lisp -*-
;; This file is loaded by Spacemacs at startup.
;; It must be stored in your home directory.

(defun dotspacemacs/layers ()
  "Configuration Layers declaration.
You should not put any user code in this function besides modifying the variable
values."
  (setq-default
   ;; Base distribution to use. This is a layer contained in the directory

Arnot

(defun filter (&rest args) ; args = list of all arguments
  (let ((factors (list -1 -1 -1
                       -1  8 -1
                       -1 -1 -1)))
    (reduce '+ (mapcar* '* factors args))))

(filter 10 20 30 40 50 60 70 80 90)
;; => 0

Arnot

(defun filter (&rest args) ; args = list of all arguments
  (let ((factors (list -1 -1 -1
                      -1  8 -1
                      -1 -1 -1)))
    (reduce '+ (map '* factors args))))