Day 4: Scratchcards
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/ or pastebin (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
- What is this?: Here is a post with a large amount of details: https://programming.dev/post/6637268
- Where do I participate?: https://adventofcode.com/
- Is there a leaderboard for the community?: We have a programming.dev leaderboard with the info on how to join in this post: https://programming.dev/post/6631465
🔒This post will be unlocked when there is a decent amount of submissions on the leaderboard to avoid cheating for top spots
🔓 Unlocked after 8 mins
Nice and easy.
Lua
-- SPDX-FileCopyrightText: 2023 Jummit -- -- SPDX-License-Identifier: GPL-3.0-or-later local function nums(str) local res = {} for num in str:gmatch("%d+") do res[num] = true end return res end local cards = {} local points = 0 for line in io.open("4.input"):lines() do local winning, have = line:match("Card%s*%d+: (.*) | (.*)") winning = nums(winning) have = nums(have) local first = true local score = 0 local matching = 0 for num in pairs(have) do if winning[num] then matching = matching + 1 if first then first = false score = score + 1 else score = score * 2 end end end points = points + score table.insert(cards, {have=have, wins=matching, count=1}) end print(points) local cardSum = 0 for i, card in ipairs(cards) do cardSum = cardSum + card.count for n = i + 1, i + card.wins do cards[n].count = cards[n].count + card.count end end print(cardSum)