this post was submitted on 06 Dec 2023
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Advent Of Code

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An unofficial home for the advent of code community on programming.dev!

Advent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.

AoC 2024

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console.log('Hello World')

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Day 6: Wait for It


Megathread guidelines

  • Keep top level comments as only solutions, if you want to say something other than a solution put it in a new post. (replies to comments can be whatever)
  • Code block support is not fully rolled out yet but likely will be in the middle of the event. Try to share solutions as both code blocks and using something such as https://topaz.github.io/paste/ , pastebin, or github (code blocks to future proof it for when 0.19 comes out and since code blocks currently function in some apps and some instances as well if they are running a 0.19 beta)

FAQ

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[โ€“] [email protected] 2 points 1 year ago

Crystal

# part 1
times = input[0][5..].split.map &.to_i
dists = input[1][9..].split.map &.to_i

prod = 1
times.each_with_index do |time, i|
	start, last = find_poss(time, dists[i])
	prod *= last - start + 1
end
puts prod

# part 2
time = input[0][5..].chars.reject!(' ').join.to_i64
dist = input[1][9..].chars.reject!(' ').join.to_i64

start, last = find_poss(time, dist)
puts last - start + 1

def find_poss(time, dist)
	start = 0
	last  = 0
	(1...time).each do |acc_time|
		if (time-acc_time)*acc_time > dist
			start = acc_time
			break
	end     end
	(1...time).reverse_each do |acc_time|
		if (time-acc_time)*acc_time > dist
			last = acc_time
			break
	end     end
	{start, last}
end