Welcome everyone to the 2023 advent of code! Thank you all for stopping by and participating in it in programming.dev whether youre new to the event or doing it again.

This is an unofficial community for the event as no official spot exists on lemmy but ill be running it as best I can with Sigmatics modding as well. Ill be running a solution megathread every day where you can share solutions with other participants to compare your answers and to see the things other people come up with


Day 1: Trebuchet?!


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


🔒This post will be unlocked when there is a decent amount of submissions on the leaderboard to avoid cheating for top spots

🔓 Edit: Post has been unlocked after 6 minutes

  • Jummit@lemmy.one
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    11 months ago

    Trickier than expected! I ran into an issue with Lua patterns, so I had to revert to a more verbose solution, which I then used in Hare as well.

    Lua:

    lua
    -- SPDX-FileCopyrightText: 2023 Jummit
    --
    -- SPDX-License-Identifier: GPL-3.0-or-later
    
    local sum = 0
    for line in io.open("1.input"):lines() do
      local a, b = line:match("^.-(%d).*(%d).-$")
      if not a then
        a = line:match("%d+")
        b = a
      end
      if a and b then
        sum = sum + tonumber(a..b)
      end
    end
    print(sum)
    
    local names = {
      ["one"] = 1,
      ["two"] = 2,
      ["three"] = 3,
      ["four"] = 4,
      ["five"] = 5,
      ["six"] = 6,
      ["seven"] = 7,
      ["eight"] = 8,
      ["nine"] = 9,
      ["1"] = 1,
      ["2"] = 2,
      ["3"] = 3,
      ["4"] = 4,
      ["5"] = 5,
      ["6"] = 6,
      ["7"] = 7,
      ["8"] = 8,
      ["9"] = 9,
    }
    sum = 0
    for line in io.open("1.input"):lines() do
      local firstPos = math.huge
      local first
      for name, num in pairs(names) do
        local left = line:find(name)
        if left and left < firstPos then
          firstPos = left
          first = num
        end
      end
      local last
      for i = #line, 1, -1 do
        for name, num in pairs(names) do
          local right = line:find(name, i)
          if right then
            last = num
            goto found
          end
        end
      end
      ::found::
      sum = sum + tonumber(first * 10 + last)
    end
    print(sum)
    
    

    Hare:

    hare
    // SPDX-FileCopyrightText: 2023 Jummit
    //
    // SPDX-License-Identifier: GPL-3.0-or-later
    
    use fmt;
    use types;
    use bufio;
    use strings;
    use io;
    use os;
    
    const numbers: [](str, int) = [
    	("one", 1),
    	("two", 2),
    	("three", 3),
    	("four", 4),
    	("five", 5),
    	("six", 6),
    	("seven", 7),
    	("eight", 8),
    	("nine", 9),
    	("1", 1),
    	("2", 2),
    	("3", 3),
    	("4", 4),
    	("5", 5),
    	("6", 6),
    	("7", 7),
    	("8", 8),
    	("9", 9),
    ];
    
    fn solve(start: size) void = {
    	const file = os::open("1.input")!;
    	defer io::close(file)!;
    	const scan = bufio::newscanner(file, types::SIZE_MAX);
    	let sum = 0;
    	for (let i = 1u; true; i += 1) {
    		const line = match (bufio::scan_line(&scan)!) {
    		case io::EOF =>
    			break;
    		case let line: const str =>
    			yield line;
    		};
    		let first: (void | int) = void;
    		let last: (void | int) = void;
    		for (let i = 0z; i < len(line); i += 1) :found {
    			for (let num = start; num < len(numbers); num += 1) {
    				const start = strings::sub(line, i, strings::end);
    				if (first is void && strings::hasprefix(start, numbers[num].0)) {
    					first = numbers[num].1;
    				};
    				const end = strings::sub(line, len(line) - 1 - i, strings::end);
    				if (last is void && strings::hasprefix(end, numbers[num].0)) {
    					last = numbers[num].1;
    				};
    				if (first is int && last is int) {
    					break :found;
    				};
    			};
    		};
    		sum += first as int * 10 + last as int;
    	};
    	fmt::printfln("{}", sum)!;
    };
    
    export fn main() void = {
    	solve(9);
    	solve(0);
    };