AdventOfCode-2018/day15.cr

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2018-12-15 02:48:35 -08:00
require "./common.cr"
lines = STDIN.gets_to_end.split("\n")
lines.pop
units = [] of NamedTuple(type: Symbol, power: Int32, hp: Int32, x: Int32, y: Int32)
lines.each_with_index do |line, y|
line.each_char_with_index do |char, x|
units << { type: :elf, power: 3, hp: 200, x: x, y: y } if char == 'E'
units << { type: :goblin, power: 3, hp: 200, x: x, y: y } if char == 'G'
end
end
map = lines.map &.chars
alias Spot = NamedTuple(x: Int32, y: Int32)
def nearby_spots(map, x, y)
spots = [] of Spot
spots << { x: x, y: y - 1} if y > 0
spots << { x: x - 1, y: y } if x > 0
spots << { x: x + 1, y: y } if x < map[0].size - 1
spots << { x: x, y: y + 1} if y < map.size - 1
return spots
end
def all_open_spots(map, units, type)
open_spots = [] of Spot
units.select &.[:type].==(type)
units.each do |unit|
next unless unit[:type] == type
x = unit[:x]
y = unit[:y]
open_spots.concat nearby_spots(map, x, y)
end
open_spots.select! do |spot|
map[spot[:y]][spot[:x]] != '#'
end
sort_reading_order(open_spots)
return open_spots
end
def sort_reading_order(collection)
collection.sort_by! do |item|
item[:y] * 100 + item[:x]
end
end
def in_range(map, units, spot, type)
nearby_spots(map, spot[:x], spot[:y]).select do |spot|
units.any? { |u| u[:x] == spot[:x] && u[:y] == spot[:y] && u[:type] == type }
end
end
def occupied(map, units, x, y)
return (map[y][x] == '#') || units.any? { |u| (u[:x] == x) && (u[:y] == y) }
end
def filter_reachable(map, units, start_spot, open_spots)
open_spots.select do |spot|
shortest_path(map, units, start_spot, spot)
end
end
def opposite_type(type)
return :goblin if type == :elf
return :elf
end
def dist(one, other)
(one[:x] - other[:x]).abs + (one[:y] - other[:y]).abs
end
def path(came_from : Hash(T|R, T|R), start : R) forall T, R
path = [ start ] of (T|R)
while came_from.has_key? start
start = came_from[start]
path << start
end
return path.reverse!
end
def astart_path(map, units, from, to)
done = Set(Spot).new
open = Set(Spot).new
start = {x: from[:x], y: from[:y] }
open << start
fscore = {} of Spot => Int32
gscore = { start => 0 }
came_from = {} of Spot => Spot
while !open.empty?
min = open.min_by { |spot| fscore[spot]? || 100000000 }
return path(came_from, min) if min == to
open.delete min
done << min
min_gscore = gscore[min]? || (100000000)
nearby_spots(map, min[:x], min[:y]).select { |spot| !occupied(map, units, spot[:x], spot[:y]) }.each do |neighbor|
next if done.includes? neighbor
neighbor_gscore = gscore[neighbor]? || (100000000)
new_score = min_gscore + 1
open << neighbor if !open.includes? neighbor
next if new_score >= neighbor_gscore
came_from[neighbor] = min
gscore[neighbor] = new_score
fscore[neighbor] = new_score + (neighbor[:y] - min[:y]) * 2 + (neighbor[:x] - min[:x]) # + (dist(neighbor, to)) # + ((neighbor[:y] - min[:y]) * 10))
end
end
end
def shortest_path(map, units, from, to)
visited = Set(Spot).new
open = Deque(Spot).new(1, { x: from[:x], y: from[:y] } )
from_hash = {} of Spot => Spot
return [{ x: from[:x], y: from[:y] }] if from[:x] == to[:x] && from[:y] == to[:y]
while !visited.includes?(to) && !open.empty?
current = open.first
open.delete current
visited << current
x, y = current[:x], current[:y]
nearby_spots(map, x, y).each do |it|
next if visited.includes? it
visited << it
next if occupied(map, units, it[:x], it[:y])
from_hash[it] = current
open << it
end
end
return path(from_hash, to) if visited.includes? to
return nil
end
def moved_unit(map, units, unit)
all_spots = all_open_spots(map, units, opposite_type(unit[:type]))
# puts "all spots: #{all_spots}"
all_spots.select! do |spot|
next true if spot[:x] == unit[:x] && spot[:y] == unit[:y]
next !occupied(map, units, spot[:x], spot[:y])
end
# puts "spots not occupied: #{all_spots}"
all_paths = all_spots.compact_map do |spot|
shortest_path(map, units, unit, spot)
end
# puts "all paths: #{all_paths}"
path = all_paths.min_by? &.size
# puts "picked path: #{path}"
new_spot = path.try &.[1]?
return unit unless new_spot
return { x: new_spot[:x], y: new_spot[:y], power: unit[:power], hp: unit[:hp], type: unit[:type] }
end
def unit_at?(units, x, y)
units.select { |u| u[:x] == x && u[:y] == y }.first?
end
def unit_at(units, x, y)
units.select { |u| u[:x] == x && u[:y] == y }.first
end
def attacked_unit(map, units, unit)
all_spots = nearby_spots(map, unit[:x], unit[:y])
enemy_spots = all_spots.select! do |spot|
next false unless enemy = unit_at?(units, spot[:x], spot[:y])
enemy[:type] == opposite_type(unit[:type])
end
return nil if enemy_spots.empty?
min_hp = enemy_spots.min_of do |spot|
unit_at(units, spot[:x], spot[:y])[:hp]
end
enemy_spots.select! do |spot|
unit_at(units, spot[:x], spot[:y])[:hp] == min_hp
end
return nil if enemy_spots.empty?
sort_reading_order(enemy_spots)
attacked_spot = enemy_spots[0]
attacked_index = units.index do |unit|
unit[:x] == attacked_spot[:x] && unit[:y] == attacked_spot[:y]
end
return nil unless attacked_index
attacked_unit = units[attacked_index]
return { attacked_index, { x: attacked_unit[:x],
y: attacked_unit[:y],
power: attacked_unit[:power],
hp: attacked_unit[:hp] - unit[:power],
type: attacked_unit[:type] } }
end
def draw(map, units)
min_x = 0
max_x = map[0].size - 1
min_y = 0
max_y = map.size - 1
(min_y..max_y).each do |y|
(min_x..max_x).each do |x|
unit = unit_at?(units, x, y)
if unit
STDOUT << ((unit[:type] == :elf) ? 'E' : 'G')
else
STDOUT << (map[y][x] == '#' ? '#' : '.')
end
end
puts
end
end
def step(map, units)
sort_reading_order(units)
index = 0
elf_death_count = 0
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while index < units.size
return nil if (units.count &.[:type].==(:elf)) == 0
return nil if (units.count &.[:type].==(:goblin)) == 0
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unit = units[index]
unit = moved_unit(map, units, unit)
units[index] = unit
attacked_u = attacked_unit(map, units, unit)
if attacked_u
attacked_index, attacked_unit = attacked_u
if attacked_unit[:hp] <= 0
elf_death_count += 1 if attacked_unit[:type] == :elf
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units.delete_at attacked_index
index -= 1 if index >= attacked_index
else
units[attacked_index] = attacked_unit
end
end
index += 1
end
return elf_death_count
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end
def check_win(units)
current_winning = nil
units.each do |u|
if current_winning
return nil if current_winning != u[:type]
else
current_winning = u[:type]
end
end
return current_winning
end
def winning_score(units, type)
units.select(&.[:type].==(type)).sum &.[:hp]
end
power = 3
loop do
simulating_units = units.dup.map do |unit|
next unit unless unit[:type] == :elf
{ x: unit[:x], y: unit[:y], hp: unit[:hp], type: :elf, power: power }
end
steps = 0
died = false
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# draw(map, simulating_units)
until won = check_win(simulating_units) || died
result = step(map, simulating_units)
if result
steps += 1
died = result > 0
end
# draw(map, simulating_units)
sort_reading_order(simulating_units)
# simulating_units.each do |unit|
# puts "health (#{unit[:type]}): #{unit[:hp]}"
# end
# puts "-- (end of roun #{steps})"
end
puts "(power: #{power}) #{steps} * #{winning_score(simulating_units, won)} = #{steps * winning_score(simulating_units, won)}"
break if !died && won != :goblin
power += 1
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end