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
|
jets = $stdin.read.strip.chars
jetp = 0
njets = jets.count
rocks = [
[ 1|2|4|8 ],
[ 2, 1|2|4, 2 ],
[ 1|2|4, 4, 4 ],
[ 1, 1, 1, 1 ],
[ 1|2, 1|2 ]
]
rockp = 0
nrocks = rocks.count
def rock_blocked(atx, aty, chamber, rock)
return true if atx < 0 || aty < 0
return true if rock.map{|row|row << atx}.any?{|row|row > 127}
rock.each_with_index do |rxs, ry|
next if chamber[aty + ry].nil?
return true if (chamber[aty + ry] & (rxs << atx)) != 0
end
return false
end
chamber = []
2022.times do
atx = 2
aty = chamber.count + 3
rock = rocks[rockp]
rockp = (rockp + 1) % nrocks
loop do
case jets[jetp]
when ?<
atx -= 1 unless rock_blocked(atx - 1, aty, chamber, rock)
when ?>
atx += 1 unless rock_blocked(atx + 1, aty, chamber, rock)
end
jetp = (jetp + 1) % njets
if rock_blocked(atx, aty - 1, chamber, rock)
rock.each_with_index do |rxs, ry|
sy = aty + ry
chamber[sy] = 0 if chamber[sy].nil?
chamber[sy] |= (rxs << atx)
end
break
else
aty -= 1
end
end
end
puts chamber.count
|
