Solving day 9 of Advent of Code 2021 in JavaScript

Advent of Code is a website that releases a new programming puzzle every day between the 1st and the 25th of December.

0:00 Part 1
16:00 Part 2

Have fun!

[mpl]

For these puzzels I really like the console.table(array) to display my inputs.

[xShosTaK]

I love watching you code this stuff right off the bat, you're crazy good. I wish you had a sub video series where you go through each day and breakdown/explain every step of the puzzles :) I know it would help me a lot! I got to the if statement on part 1 and you broke my brain haha. But you definitely give me something to google search and look at for hours on end haha. Thank you for these.

[annsofipettersson]

I think instead of looping through all places to floodfill you can just start in your low points from part 1. Anyway as always great walk through! :) Been following you since last year and you have a similar way of solving the problems and I also do it in js so nice to see how you do it and also learn some new stuff!

[queuebit]

Thanks for sharing your walkthrough.

I'll have to check it out again to see what situation I am not handling with part 2.

[ans]

Amazing video once more, I like to see the way you go through each problem, and it sometimes reflects the way I solved it or else I get to learn a new technique, or a term in this case (floodfill) I used floodfill in my solution without realizing it.

I do it in python and have tried to learn Js but quit because I didn't find it interesting nut after watching your videos I wanna learn JS again, thank u for the motivation. I also watch another Youtuber who di AoC in Java. Its nice to see and underastand how other languages work as well

[rowolta]

For part 1 I did a get function, where you do not have to care for the matrix boundaries. Is the value undefined it is outside and thus greater than the value.

const get = (a, x, y) => (a[y] || [])[x];
const isGreat = (less) => (than) => {
if (than === undefined) return true;
return less < than;
};
const solve1 = (a) => {
let res = 0;
for (let y = 0; y < a.length; y += 1) {
for (let x = 0; x < a[y].length; x += 1) {
const num = get(a, x, y);
if ([
get(a, x - 1, y),
get(a, x, y - 1),
get(a, x + 1, y),
get(a, x, y + 1),
].every(isGreat(num))
) {
res += num + 1;
}
}
}
return res;
};

[asf]

Good job, keep going , can zoom in vscode please 🙏