day-2

awk/day-1/test.sh

@@ -19,10 +19,10 @@ set -e
 
 PATH="$(pwd):${PATH}"
 
-source ../../aoc-utils.sh
+source ../aoc-utils.sh
 
-aoc_expect part-1.awk ../test-input.txt 24000
+aoc_expect part-1.awk ../../input/day-1-example.txt 24000
-aoc_expect part-2.awk ../test-input.txt 45000
+aoc_expect part-2.awk ../../input/day-1-example.txt  45000
 
-aoc_expect part-1.awk ../input.txt 68292
+aoc_expect part-1.awk ../../input/day-1.txt 68292
-aoc_expect part-2.awk ../input.txt 203203
+aoc_expect part-2.awk ../../input/day-1.txt 203203

elisp/advent-of-code.el

@@ -25,7 +25,13 @@
 
 (defmacro aoc-debug (expr)
   `(let ((e ,expr))
-     (debug e)
+     (princ (format "%s\n\n" e) 'external-debugging-output)
+     (unless noninteractive
+       (debug e))
      e))
 
-(provide 'aoc)
+(provide 'advent-of-code)
+
+;; Local Variables:
+;; read-symbol-shorthands: (("aoc-" . "advent-of-code-"))
+;; End:

elisp/day-1/solution.el

@@ -17,15 +17,15 @@
 ;; You should have received a copy of the GNU General Public License
 ;; along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-(add-to-list 'load-path "../../")
+(add-to-list 'load-path "../")
 
 (require 'ert)
 (require 'cl-lib)
 (require 'aoc)
 
-(defvar input-file "../input.txt")
+(defvar input-file "../../input/day-1.txt")
 
-(defvar test-input-file "../test-input.txt")
+(defvar test-input-file "../../input/day-1-example.txt")
 
 (defun eat (data)
   (let ((lines (string-lines data)))

elisp/day-2/solution.el

@@ -0,0 +1,141 @@
+#!/usr/bin/env -S emacs --script
+
+;; -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2022 notroot
+
+;; This program is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+(add-to-list 'load-path "../")
+
+(require 'ert)
+(require 'advent-of-code)
+
+(defvar solution-example-input
+  "../../input/day-2-example.txt")
+
+(defvar solution-input
+  "../../input/day-2.txt")
+
+(defvar solution-shapes
+  '(rock paper scissors))
+
+(defvar solution-outcomes
+  '(win lose draw))
+
+(defvar solution-opponent-letter-to-shape-alist
+  '(("A" . rock)
+    ("B" . paper)
+    ("C" . scissors)))
+
+(defvar solution-player-letter-to-shape-alist
+  '(("X" . rock)
+    ("Y". paper)
+    ("Z" . scissors)))
+
+(defvar solution-player-letter-to-outcome-alist
+  '(("X" . lose)
+    ("Y" . draw)
+    ("Z" . win)))
+
+(defvar solution-shape-score-alist
+  '((rock . 1)
+    (paper . 2)
+    (scissors . 3)))
+
+(defvar solution-outcome-score-alist
+  '((win . 6)
+    (draw . 3)
+    (lose . 0)))
+
+;; Each shape points to another shape creating a cyclical list.
+;; Each shape points to the shape that it beats, so deciding a game
+;; outcome is a simple list search!
+
+(defvar solution-shape-outcome-alist
+  '((rock . scissors)
+    (scissors . paper)
+    (paper . rock)))
+
+(defun solution-decide-game (a b)
+  (cond ((equal a b)
+         'draw)
+        ((equal (cdr (assoc a solution-shape-outcome-alist)) b)
+         'win)
+        (t
+         'lose)))
+
+(defun solution-shape-for-outcome (a outcome)
+  (pcase outcome
+    ('lose
+     (cdr (assoc a solution-shape-outcome-alist)))
+    ('draw
+     a)
+    ('win
+     (car (seq-find (lambda (c)
+                      (equal (cdr c) a))
+                    solution-shape-outcome-alist)))))
+
+(defun solution-part-1 (input)
+  (let ((rows (seq-map (lambda (s)
+                         (string-split s " " t))
+                       input)))
+    (seq-reduce (lambda (acc row)
+                  (let* ((their-shape (cdr (assoc (nth 0 row) solution-opponent-letter-to-shape-alist)))
+                         (our-shape (cdr (assoc (nth 1 row) solution-player-letter-to-shape-alist)))
+                         (outcome (solution-decide-game our-shape their-shape)))
+                    (+ acc
+                       (cdr (assoc our-shape solution-shape-score-alist))
+                       (cdr (assoc outcome solution-outcome-score-alist)))))
+                rows
+                0)))
+
+(defun solution-part-2 (input)
+  (let ((rows (seq-map (lambda (s)
+                         (string-split s " " t))
+                       input)))
+    (seq-reduce (lambda (acc row)
+                  (let* ((their-shape (cdr (assoc (nth 0 row) solution-opponent-letter-to-shape-alist)))
+                         (desired-outcome (cdr (assoc (nth 1 row) solution-player-letter-to-outcome-alist)))
+                         (our-shape (solution-shape-for-outcome their-shape desired-outcome)))
+                    (+ acc
+                       (cdr (assoc our-shape solution-shape-score-alist))
+                       (cdr (assoc desired-outcome solution-outcome-score-alist)))))
+                rows
+                0)))
+
+
+(ert-deftest solution-test-decide-game ()
+  (should (equal (solution-decide-game 'rock 'paper) 'lose))
+  (should (equal (solution-decide-game 'paper 'rock) 'win))
+  (should (equal (solution-decide-game 'rock 'rock) 'draw)))
+
+(ert-deftest solution-test-part-1-example ()
+  (should (equal (solution-part-1 (aoc-read-file-lines solution-example-input)) 15)))
+
+(ert-deftest solution-test-part-1-input ()
+  (should (equal (solution-part-1 (aoc-read-file-lines solution-input)) 12740)))
+
+(ert-deftest solution-test-part-2-example ()
+  (should (equal (solution-part-2 (aoc-read-file-lines solution-example-input)) 12)))
+
+(ert-deftest solution-test-part-2 ()
+  (should (equal (solution-part-2 (aoc-read-file-lines solution-input)) 11980)))
+
+(when noninteractive
+  (ert-run-tests-batch-and-exit))
+
+;; Local Variables:
+;; read-symbol-shorthands: (("solution-" . "advent-of-code-day-2-") ("aoc-" . "advent-of-code-"))
+;; End:

input/day-2-example.txt

@@ -0,0 +1,3 @@
+A Y
+B X
+C Z