diff --git a/elisp/day-5/advent-of-code.el b/elisp/day-5/advent-of-code.el new file mode 120000 index 0000000..4a02002 --- /dev/null +++ b/elisp/day-5/advent-of-code.el @@ -0,0 +1 @@ +../advent-of-code.el \ No newline at end of file diff --git a/elisp/day-5/example.txt b/elisp/day-5/example.txt new file mode 120000 index 0000000..17eef44 --- /dev/null +++ b/elisp/day-5/example.txt @@ -0,0 +1 @@ +../../input/day-5-example.txt \ No newline at end of file diff --git a/elisp/day-5/input.txt b/elisp/day-5/input.txt new file mode 120000 index 0000000..6f708d3 --- /dev/null +++ b/elisp/day-5/input.txt @@ -0,0 +1 @@ +../../input/day-5.txt \ No newline at end of file diff --git a/elisp/day-5/solution.el b/elisp/day-5/solution.el new file mode 100755 index 0000000..a56080f --- /dev/null +++ b/elisp/day-5/solution.el @@ -0,0 +1,120 @@ +#!/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 . + +(add-to-list 'load-path default-directory) + +(require 'cl-lib) +(require 'eieio) +(require 'ert) +(require 'advent-of-code) + +(defmacro -make-crates (&rest exprs) + `(make-advent-of-code-day-5-crates ,@exprs)) + +(cl-defstruct -crates + stacks) + +(defun -crates-pop (crates n) + (with-slots (stacks) crates + (when-let ((stack (assoc n stacks))) + (pop (cdr stack))))) + +(defun -crates-push (crates crate n) + (with-slots (stacks) crates + (if-let ((stack (assoc n stacks))) + (push crate (cdr stack)) + (push (cons n (list crate)) stacks)))) + +(defun -crates-append (crates crate n) + (with-slots (stacks) crates + (if-let ((stack (assoc n stacks))) + (setf (cdr stack) (append (cdr stack) (list crate))) + (push (cons n (list crate)) stacks)))) + +(defun -crates-process-move (crates move) + (with-slots (n from to) move + (cl-loop repeat n + do (-crates-push crates (-crates-pop crates (- from 1)) (- to 1))))) + +(defun -crates-from-list (input) + (cl-loop for (crate . n) in input + with crates = (-make-crates :stacks nil) + do (-crates-append crates crate n) + finally (return crates))) + +(defmacro -make-move (&rest exprs) + `(make-advent-of-code-day-5-move ,@exprs)) + +(cl-defstruct -move + n from to) + +(defun -parse-input-into-parts (input) + (let* ((delimiter (seq-position input "" 'string=)) + (crates (seq-subseq input 0 (- delimiter 1))) + (moves (seq-subseq input (+ delimiter 1)))) + (list crates moves))) + +(defun -parse-crates-from-line (line) + (cl-loop for i from 0 to (- (length line) 3) by 4 + for n from 0 + for crate = (substring line i (+ i 3)) + for crate-id = (substring crate 1 2) + for empty? = (not (string-match-p "[^\s\n]" crate)) + if (not empty?) + collect (cons crate-id n))) + +(defun -parse-move-from-line (line) + (save-match-data + (string-match (rx "move" space (group (one-or-more digit)) space + "from" space (group (one-or-more digit)) space + "to" space (group (one-or-more digit))) + line) + (list (string-to-number (match-string 1 line)) + (string-to-number (match-string 2 line)) + (string-to-number (match-string 3 line))))) + +(defun -part-1 (input) + (pcase-let* ((`(,input-crates ,input-moves) (-parse-input-into-parts input)) + (parsed-crates-list (cl-loop for line in input-crates + append (-parse-crates-from-line line))) + (crates (-crates-from-list parsed-crates-list)) + (moves (cl-loop for line in input-moves + for move = (pcase-let ((`(,n ,from ,to) (-parse-move-from-line line))) + (-make-move :n n :from from :to to)) + collect move))) + (seq-do (lambda (move) + (-crates-process-move crates move)) + moves) + (cl-loop for n from 0 to (length (-crates-stacks crates)) + for top-crate = (cadr (assoc n (-crates-stacks crates))) + for top-crates = top-crate then (concat top-crates top-crate) + finally (return top-crates)))) + +(ert-deftest -test-part-1-example () + (should (equal (-part-1 (aoc-read-file-lines "example.txt")) "CMZ"))) + +(ert-deftest -test-part-1 () + (should (equal (-part-1 (aoc-read-file-lines "input.txt")) "CFFHVVHNC"))) + +(when noninteractive + (ert-run-tests-batch)) + +;; Local Variables: +;; read-symbol-shorthands: (("-" . "advent-of-code-day-5-") ("aoc-" . "advent-of-code-")) +;; End: