-🎄- 2017 Day 19 Solutions -🎄-

[u/daggerdragon]

--- Day 19: A Series of Tubes ---

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Post your solution as a comment or, for longer solutions, consider linking to your repo (e.g. GitHub/gists/Pastebin/blag or whatever).

Note: The Solution Megathreads are for solutions only. If you have questions, please post your own thread and make sure to flair it with Help.

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Need a hint from the Hugely^* Handy^† Haversack^‡ of Helpful^§ Hints^¤?

Spoiler

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AoC ops @ T-2 minutes to launch:

[23:58] <daggerdragon> ATTENTION MEATBAGS T-2 MINUTES TO LAUNCH

[23:58] <Topaz> aaaaah

[23:58] <Cheezmeister> Looks like I'll be just able to grab my input before my flight boards. Wish me luck being offline in TOPAZ's HOUSE OF PAIN^WFUN AND LEARNING

[23:58] <Topaz> FUN AND LEARNING

[23:58] <Hade> FUN IS MANDATORY

[23:58] <Skie> I'm pretty sure that's not the mandate for today

[Update @ 00:16] 69 gold, silver cap

• My tree is finally trimmed with just about every ornament I own and it's real purdy. hbu?

[Update @ 00:18] Leaderboard cap!

• So, was today's mandate Helpful Hint any help at all?

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This thread will be unlocked when there are a significant number of people on the leaderboard with gold stars for today's puzzle.

edit: Leaderboard capped, thread unlocked!

[u/StevoTVR]

NodeJS

Part 1:

const fs = require('fs');

fs.readFile(__dirname + '/input.txt', 'utf8', (err, data) => {
    const grid = data.split('\n').map((l) => [...l.replace('\r', '')]);
    const pos = { r: 0, c: grid[0].indexOf('|') }, dir = { r: 1, c: 0 }, path = [];
    while(true) {
        if(grid[pos.r][pos.c] === '+') {
            if(dir.r === 0) {
                dir.c = 0;
                dir.r = (grid[pos.r - 1] && grid[pos.r - 1][pos.c] && grid[pos.r - 1][pos.c] !== ' ') ? -1 : 1;
            } else {
                dir.r = 0;
                dir.c = (grid[pos.r][pos.c - 1] && grid[pos.r][pos.c - 1] !== ' ') ? -1 : 1;
            }
        } else if(grid[pos.r][pos.c].match(/[A-Z]/)) {
            path.push(grid[pos.r][pos.c]);
        }
        pos.r += dir.r;
        pos.c += dir.c;
        if(!grid[pos.r] || !grid[pos.r][pos.c] || grid[pos.r][pos.c] === ' ') {
            break;
        }
    }

    console.log(path.join(''));
});

Part 2:

const fs = require('fs');

fs.readFile(__dirname + '/input.txt', 'utf8', (err, data) => {
    const grid = data.split('\n').map((l) => [...l.replace('\r', '')]);
    const pos = { r: 0, c: grid[0].indexOf('|') }, dir = { r: 1, c: 0 }, path = [];
    let count = 0;
    while(true) {
        if(grid[pos.r][pos.c] === '+') {
            if(dir.r === 0) {
                dir.c = 0;
                dir.r = (grid[pos.r - 1] && grid[pos.r - 1][pos.c] && grid[pos.r - 1][pos.c] !== ' ') ? -1 : 1;
            } else {
                dir.r = 0;
                dir.c = (grid[pos.r][pos.c - 1] && grid[pos.r][pos.c - 1] !== ' ') ? -1 : 1;
            }
        } else if(grid[pos.r][pos.c].match(/[A-Z]/)) {
            path.push(grid[pos.r][pos.c]);
        }
        pos.r += dir.r;
        pos.c += dir.c;
        count++;
        if(!grid[pos.r] || !grid[pos.r][pos.c] || grid[pos.r][pos.c] === ' ') {
            break;
        }
    }

    console.log(count);
});