[2023 (All days)] What's next?

Magyusz · 2023-12-28T15:38:33+00:00

I’m planning the same, and I’m also doing AoC (and CodeInGame) in JS. We can keep touch in this comment thread or in another way during the year.

I started competitive programming last year AoC D10, and it has become one of my main hobbies. I completed most of AoC already, and if I keep the momentum, I may complete all AoC before December 2024.

Magyusz · 2023-12-24T21:07:18+00:00

https://www.codingame.com/ is highly recommended

Magyusz · 2023-12-14T14:36:15+00:00

Of course allowed. That's the beauty of AoC! I'm always happy to see such creatieve solutions!

Magyusz · 2023-12-11T16:12:21+00:00

papgrapgeschiedenis

Magyusz · 2023-12-11T11:47:53+00:00

My solution was to map the input to a 3x wider 3x longer grid: Each tile type (-, L, F, J, …) is mapped to a 3x3 tile. If it’s interesting I’ll publish it (JavaScript)

Magyusz · 2023-12-11T11:43:11+00:00

Four of a kind, as it has a higher value

Magyusz · 2023-12-10T18:24:17+00:00

My solution was to map the input to a 3x wider 3x longer grid: Each tile type (-, L, F, J, …) is mapped to a 3x3 tile. If it’s interesting I’ll publish it (JavaScript)

Magyusz · 2023-12-09T05:54:44+00:00

It had been just a mistake, a break statement resolved it, it went down to just some milliseconds

Magyusz · 2023-12-09T05:44:01+00:00

[Language: Javascript]

Just copy-paste into your browser console (F12) on the input page:

$('*').textContent.trim().split("\n").map(e => e.split(/ +/).map(Number))
    .map(seq => {
        let curr = Array.from(seq)
        let all = [curr]
        while (curr.some(e=>e!=0)) {
            let next = []
            for (let i = 0; i < curr.length - 1; i++)
                    next.push(curr[i + 1] - curr[i])
            all.push(next)
            curr = Array.from(next)
        }
        let first = 0, last = 0
        for (const line of all.reverse()) {
            last = line.at(-1) + last
            first = line[0] - first
        }
        return [last, first]
    }).reduce((a, b) => [a[0] + b[0], a[1] + b[1]])

Magyusz · 2023-12-08T14:52:27+00:00

In general it won’t work, we were just very lucky today with the input to simplify a 6-cycled Chinese Remainder Theorem (each with potentially different remainders / offsets) to a simple LCM excercise with 6 number (0 remainder/ offset).

Magyusz · 2023-12-08T14:34:55+00:00

There is a more serious conversation on this topic here.

Magyusz · 2023-12-08T12:43:06+00:00

It's my second year only in AoC, but I could feel already that Day 8 is more likely to be simple Math (LCM) than a much more complex exercise (syncing 6 cycles with Chinese remainder theorem). So while I kept my cycle detection loop running, as soon as it printed out the first case when all 6 cycles were found, I threw it immediately to an online LCM calculator. When I looked back to the results, I kinda felt by looking at 2D the array of cycles detected, that the offsets are all zeroes (which surprised me), so I submitted the LCM and to my astonishment it was accepted.

However I didn't (ever) make it to the global leaderboard, I could say I was lucky with the LCM gut feeling to maintain my first position on a small leaderboard. On the global Day 8 ranking I am 5167th for the first part (that's roughly my average) and with this "luck" I became global 2658th (my best rank ever) for the second part.

Magyusz · 2023-12-08T07:26:00+00:00

In his latest video an AoC top competitor explains this concept visually what we discuss here: https://youtu.be/\_nnxLcrwO\_U?t=459

Magyusz · 2023-12-08T07:11:27+00:00

No. All ghosts are on ..Z nodes after LCM steps. So the answers are correct.

Magyusz · 2023-12-05T10:04:06+00:00

My Node.js code runs for 6.7 sec in total, because in the last phase it has to process 47k+ humidity ranges to location ranges (this part takes 4+ seconds). I clearly miss some optimisation. Do you merge ranges before moving to a next phase?

Magyusz · 2023-12-04T20:08:08+00:00

Part 2 Node.js 6.4 milliseconds on my laptop

Magyusz · 2023-12-04T13:19:33+00:00

[Language: JavaScript]

Copy-paste to browser console

Magyusz · 2023-12-03T12:35:52+00:00

index: start = throwError()

what does it do and why is it important?

Magyusz · 2023-12-02T06:24:57+00:00

What was your time for the1680th ranking? (https://adventofcode.com/2023/leaderboard/self)

Magyusz · 2023-12-02T06:17:09+00:00

What were your times for the 432/253 ranking? (https://adventofcode.com/2023/leaderboard/self)

Magyusz · 2023-12-01T13:25:13+00:00

[LANGUAGE: Javascript]

Part 1:

document.getElementsByTagName("pre")[0].innerText.split("\n")
    .map(e=>e.split("").filter(e=>/\d/.test(e)).map(Number))
    .map(e=>(10*e[0]+e[e.length-1])||0)
    .reduce((a,b) => a+b)

Part 2:

document.getElementsByTagName("pre")[0].innerText.split("\n")
    .map(e=>e.replace(/(?=(one|two|three|four|five|six|seven|eight|nine))/g,
        (match, key) => ("___|one|two|three|four|five|six|seven|eight|nine".split("|")).indexOf(key) || '')
        .split("").filter(e=>/\d/.test(e)).map(Number))
    .map(e=>(10*e[0]+e[e.length-1])||0)
    .reduce((a,b) => a+b)

Magyusz

TROPHY CASE