Add solutions to days 10 and 11

This commit is contained in:
Danila Fedorin 2020-12-11 11:32:33 -08:00
parent 17492a8c23
commit 479affa4cc
2 changed files with 101 additions and 0 deletions

37
day10.cr Normal file
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require "advent"
INPUT = input(2020, 10).lines.map(&.to_i32).sort!
def part1(input)
diff_1 = 0
diff_3 = 0
curr = 0
input << (input.max + 3)
input.each do |i|
diff_1 += 1 if (i - curr) == 1
diff_3 += 1 if (i - curr) == 3
curr = i
end
puts diff_1 * diff_3
end
def count_ways(input, prev, index, mem, indent = 0)
if m = mem[{prev, index}]?
return m
end
return 0_i64 if input[index] - prev > 3 || index >= input.size
return 1_i64 if index == input.size - 1
total = count_ways(input, input[index], index+1, mem, indent + 1)
total += count_ways(input, prev, index+1, mem, indent + 1)
mem[{prev, index}] = total
return total
end
def part2(input)
input << (input.max + 3)
count_ways(input, 0, 0, {} of {Int32, Int32} => Int64)
end
puts part1(INPUT.clone)
puts part2(INPUT.clone)

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day11.cr Normal file
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require "advent"
INPUT = input(2020, 11).lines.map(&.chars)
abstract class Search
def search(current, x, y, dx, dy)
x, y = x + dx, y + dy
return 0 if y < 0 || y >= current.size
return 0 if x < 0 || x >= current[y].size
search_impl(current,x,y,dx,dy)
end
abstract def search_impl(current, x, y, dx, dy)
end
class FirstSearch < Search
def search_impl(current, x, y, dx, dy)
return current[y][x] == '#' ? 1 : 0
end
end
class SecondSearch < Search
def search_impl(current, x, y, dx, dy)
return 1 if current[y][x] == '#'
return 0 if current[y][x] == 'L'
return search(current, x, y, dx, dy)
end
end
DIRS = [{-1,-1}, {-1, 0}, {-1, 1}, {0, -1}, {0, 1}, {1, -1}, {1, 0}, {1,1}]
def step(current, step, check, n)
current.each_with_index do |row, y|
row.each_with_index do |seat, x|
step[y][x] = current[y][x]
count = DIRS.sum do |dx, dy|
check.search(current, x, y, dx, dy)
end
step[y][x] = 'L' if seat == '#' && count >= n
step[y][x] = '#' if seat == 'L' && count == 0
end
end
{step, current}
end
def run(input, search, n)
current = input
step = input.clone
loop do
current, step = step(current, step, search, n)
break if current.zip_with(step) { |l, r| l == r }.all?
end
current.sum(&.count(&.==('#')))
end
def part1(input)
run(input, FirstSearch.new, 4)
end
def part2(input)
run(input, SecondSearch.new, 5)
end
puts part1(INPUT.clone)
puts part2(INPUT.clone)