blob: 9dc724b5908e22cab3b00d1497c9fa3c0810a977 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
(defstruct board ()
w h a s
(:postinit (bo)
(set bo.s (* bo.w bo.h)))
(:method count-flashes (bo)
(sum bo.a (op countql #\0)))
(:method all-flash (bo)
(eql bo.s bo.(count-flashes)))
(:method lambda (me x y)
(if (or (minusp x)
(minusp y)
(<= me.w x)
(<= me.h y))
#\0
[[me.a y] x]))
(:method lambda-set (me x y nv)
(unless (or (minusp x)
(minusp y)
(<= me.w x)
(<= me.h y))
(set [[me.a y] x] nv))))
(defmacro forxy (x y bo . body)
^(each-prod ((,y 0..(qref ,bo h))
(,x 0..(qref ,bo w)))
,*body))
(defmacro incnz (place)
(with-gensyms (p)
^(placelet ((,p (read-once ,place)))
(if (eql #\0 ,p) #\0 (inc ,p)))))
(defmacro mincnz (. places)
^(progn ,*(mapcar (ret ^(incnz ,@1)) places)))
(defun read-board-file (: (name "input"))
(flow (file-get-lines name)
vec-list
(new board
h (len @1)
w (len (first @1))
a @1)))
(defmeth board step (bo)
(forxy x y bo
(inc [bo x y]))
(let ((flashed t))
(while flashed
(zap flashed)
(forxy x y bo
(when (> [bo x y] #\9)
(set flashed t
[bo x y] #\0)
(let ((x- (pred x)) (x+ (succ x))
(y- (pred y)) (y+ (succ y)))
(mincnz [bo x- y-] [bo x y-] [bo x+ y-]
[bo x- y] [bo x+ y]
[bo x- y+] [bo x y+] [bo x+ y+]))))))
bo)
(defun solve-part-one (: (name "input"))
(let ((bo (read-board-file name))
(tf 0))
(dotimes (i 100 tf)
(inc tf bo.(step).(count-flashes)))))
(defun solve-part-two (: (name "input"))
(for ((bo (read-board-file name))
(i 0))
((not bo.(all-flash)) i)
(bo.(step)
(inc i))))
|
