blob: 7dd3531d7c8950ff4791330841109f586848c564 (
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
|
class Sensor
def initialize(sx, sy, bx, by)
@x = sx
@y = sy
@range = (sx - bx).abs + (sy - by).abs
end
attr_reader :x, :y, :range
end
sensors = []
beacons = []
$stdin.readlines.each do |line|
c = line.scan(/x=(-?\d+), y=(-?\d+)/).flatten.map(&:to_i)
sensors << Sensor.new(*c)
beacons << c[2..3]
end
row = 2_000_000
xranges = []
sensors.each do |s|
dx = s.range - (s.y - row).abs
xranges << ((s.x - dx)..(s.x + dx)) if dx > 0
end
from = xranges.map(&:begin).min
to = xranges.map(&:end).max
xs = to - from + 1
(from..to).each do |x|
xs += 1 unless xranges.any? { |xrange| xrange.include?(x) }
end
xs -= beacons.select { |_, y| y == row }.map { |x, _| x }.uniq.count
pp xs
|
