From d2baefb50686fb85a41250a5889e9bc305c177f0 Mon Sep 17 00:00:00 2001
From: haskal <haskal@awoo.systems>
Date: Mon, 14 Dec 2020 00:27:19 -0500
Subject: [PATCH] day 14: lol half of this is currently commented

---
 14.rkt | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 14.rkt

diff --git a/14.rkt b/14.rkt
new file mode 100644
index 0000000..b791256
--- /dev/null
+++ b/14.rkt
@@ -0,0 +1,79 @@
+#lang curly-fn racket
+
+(require "scripts/aoc.rkt")
+
+;; solution for day 14
+
+(define (part1 input)
+  (void))
+  ; (define (parse-mask msk)
+  ;   (define orval (for/fold ([val 0]) ([chr (in-string msk)])
+  ;                   (+ (* val 2) (if (equal? chr #\1) 1 0))))
+  ;   (define andval (for/fold ([val 0]) ([chr (in-string msk)])
+  ;                    (+ (* val 2) (if (equal? chr #\0) 0 1))))
+  ;   (cons orval andval))
+  ; (define orval 0)
+  ; (define andval (sub1 (expt 2 37)))
+  ; (define mem (make-hash))
+  ; (for ([ins (in-list input)])
+  ;   (match ins
+  ;     [(cons 'mask (cons ov av)) (set! orval ov) (set! andval av)]
+  ;     [(cons 'set (cons addr val))
+  ;      (define new-val (bitwise-ior (bitwise-and val andval) orval))
+  ;      (hash-set! mem addr new-val)]))
+  ; (for/sum ([(k v) (in-hash mem)])
+  ;   v))
+
+(define (addr->bits addr)
+  (vector-copy 
+  (for/vector ([i (in-range 36)])
+    (bitwise-and 1 (arithmetic-shift addr (+ -35 i))))))
+(define (bits->addr bits)
+  (for/fold ([val 0]) ([bit (in-vector bits)])
+    (+ (* val 2) bit)))
+
+(define (part2 input)
+  (define mem (make-hash))
+  (define mask #f)
+  (for ([ins (in-list input)])
+    (match ins
+      [(cons 'mask m) (set! mask m) (displayln mask)]
+      [(cons 'set (cons addr val))
+       (define addr-bits (addr->bits addr))
+       (for ([chr (in-string mask)] [i (in-naturals)])
+         (when (equal? chr #\1)
+           (vector-set! addr-bits i 1)))
+       (define addrs-set (list addr-bits))
+       (for ([chr (in-string mask)] [i (in-naturals)])
+         (when (equal? chr #\X)
+           (define ones (map (lambda (x) (define y (vector-copy x)) (vector-set! y i 1) y)
+                             addrs-set))
+           (define zeros (map (lambda (x) (define y (vector-copy x)) (vector-set! y i 0) y)
+                             addrs-set))
+           (set! addrs-set (append ones zeros))))
+       (for ([addr (in-list addrs-set)])
+         (hash-set! mem (bits->addr addr) val))]))
+
+  (for/sum ([(k v) (in-hash mem)])
+    v))
+
+;; parse input file
+(define (parse fname)
+  (define input (file->lines fname))
+  (for/list ([i (in-list input)])
+    (match i
+      [(pregexp #px"^mask = (.*?)$" (list _ mask)) (cons 'mask mask)]
+      [(pregexp #px"^mem\\[([0-9]+)\\] = ([0-9]+)$" (list _ addr val))
+       (cons 'set (cons (string->number addr) (string->number val)))]
+      [_ (error "not shonks i")])))
+
+(module+ test
+  (require rackunit)
+  ;; tests here
+  (displayln "no tests :("))
+
+(module+ main
+  (define input (parse "inputs/14"))
+  (answer 14 1 (time (part1 input)))
+  (answer 14 2 (time (part2 input)))
+  (displayln "meow"))