Advent of Code: 2024 Day 11 / Jo Wood

Professor of Visual Analytics interested in design, geovisualization, visual storytelling and computational thinking.

Public

Edited

Dec 22

Paused

function blink(n) {

if (n === 0) {

return [1];

}

const len = Math.floor(Math.log10(n) + 1);

if (len % 2 === 0) {

const div = 10 ** (len / 2);

return [Math.floor(n / div), n % div];

}

return [n * 2024];

}

function parse(input) {

return input.split(/\s+/).map((d) => [Number(d), 1]);

}

function countStones(stones, n) {

for (let i = 0; i < n; i++) {

const freqs = new Map();

stones.forEach(([stone, freq]) => {

blink(stone).forEach((newStone) => {

freqs.set(newStone, (freqs.get(newStone) || 0) + freq);

});

stones = [...freqs.entries()];

}

return d3.sum(stones, (d) => d[1]);

}

function part1(input) {

return countStones(parse(input), 25);

}

function part2(input) {

return countStones(parse(input), 75);

}

Experiment and prototype by building visualizations in live JavaScript notebooks. Collaborate with your team and decide which concepts to build out.

Use Observable Framework to build data apps locally. Use data loaders to build in any language or library, including Python, SQL, and R.

Seamlessly deploy to Observable. Test before you ship, use automatic deploy-on-commit, and ensure your projects are always up-to-date.