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
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
|
input = io.lines('input.txt')
active = 0
world = {}
function copy(world)
new_world = {}
for x = -world.bounds[1], world.bounds[1] do
for y = -world.bounds[2], world.bounds[2] do
for z = -world.bounds[3], world.bounds[3] do
set(new_world, x, y, z, get(world, x, y, z))
end
end
end
new_world.bounds = {}
for i, b in pairs(world.bounds) do
new_world.bounds[i] = b
end
return new_world
end
function iterate(world, f)
for x = -world.bounds[1], world.bounds[1] do
for y = -world.bounds[2], world.bounds[2] do
for z = -world.bounds[3], world.bounds[3] do
f(x, y, z, get(world, x, y, z))
end
end
end
end
function set(world, x, y, z, value)
if not world[x] then
world[x] = {}
end
if not world[x][y] then
world[x][y] = {}
end
world[x][y][z] = value
return world
end
function get(world, x, y, z)
if not world[x] then
return '.'
elseif not world[x][y] then
return '.'
elseif not world[x][y][z] then
return '.'
else
return world[x][y][z]
end
end
function step_cell(world, x, y, z)
active = 0
for dx = -1, 1 do
for dy = -1, 1 do
for dz = -1, 1 do
if not (dx == 0 and dy == 0 and dz == 0) then
if get(world, x+dx, y+dy, z+dz) == '#' then
active = active + 1
end
end
end
end
end
if get(world, x, y, z) == '#' then
if active == 2 or active == 3 then
return '#'
else
return '.'
end
else
if active == 3 then
return '#'
else
return '.'
end
end
end
i = 0
for line in input do
for j = 1, line:len() do
set(world, i, j, 0, line:sub(j, j))
end
i = i + 1
end
world.bounds = { i, i, 1 }
function bump(bounds)
return { bounds[1]+1, bounds[2]+1, bounds[3]+1 }
end
for round = 1, 6 do
new_world = {}
new_world.bounds = bump(world.bounds)
iterate(new_world, function (x, y, z, value)
set(new_world, x, y, z, step_cell(world, x, y, z))
end)
world = copy(new_world)
end
count = 0
iterate(world, function (x, y, z, value)
if value == '#' then
count = count + 1
end
end)
print(count)
|