src/2019/days/day-17.lisp @ cb7df3835cd1
Remove unused code, add comment
author |
Steve Losh <steve@stevelosh.com> |
date |
Fri, 17 Dec 2021 20:52:02 -0500 |
parents |
ff7c8ed35992 |
children |
(none) |
(advent:defpackage* :advent/2019/17)
(in-package :advent/2019/17)
(defclass* world ()
((tiles :initform (make-hash-table))
robot-pos
robot-dir))
(defun record-string (program)
(gathering-vector (:element-type 'character)
(advent/intcode:run program :output (compose #'gather #'code-char))))
(defun parse-char (char)
(case char
(#\^ (values #\# #c( 0 -1)))
(#\v (values #\# #c( 0 1)))
(#\< (values #\# #c(-1 0)))
(#\> (values #\# #c( 1 0)))
(t (values char nil))))
(defun robot-char (dir)
(ecase dir
(#c( 0 -1) #\^)
(#c( 0 1) #\v)
(#c(-1 0) #\<)
(#c( 1 0) #\>)))
(defun parse-map (string)
(iterate
(with world = (make-instance 'world))
(for line :in (split-sequence:split-sequence #\newline string
:remove-empty-subseqs t))
(for row :from 0)
(iterate
(for char :in-string line :with-index col)
(for pos = (complex row col))
(for (values tile dir) = (parse-char char))
(setf (gethash pos (tiles world)) tile)
(when dir
(setf (robot-pos world) pos
(robot-dir world) dir)))
(returning world)))
(defun intersectionp (world pos)
(every (lambda (x)
(eql #\# (gethash x (tiles world))))
(manhattan-neighborhood pos)))
(defun intersections (world)
(remove-if-not (curry #'intersectionp world)
(alexandria:hash-table-keys (tiles world))))
(defun alignment-parameter (pos)
(* (realpart pos)
(imagpart pos)))
(defun draw-world (world)
(print-hash-table-map (tiles world)
:swap-axes t
:flip-y t
:extra (lambda (pos)
(cond ((= pos (robot-pos world))
(robot-char (robot-dir world)))
((intersectionp world pos) #\O)))))
(define-problem (2019 17) (data read-numbers) (7328)
;; (advent/intcode::disassemble-program (advent/intcode:init data))
(let ((world (parse-map (record-string data))))
;; (draw-world world)
(summation (intersections world) :key #'alignment-parameter)))
#; Scratch --------------------------------------------------------------------