function process(n) {
n ^= (n << 6) & 0xffffff; // Multiply by 64
n ^= (n >>> 5) & 0xffffff; // Divide by 32
n ^= (n << 11) & 0xffffff; // Multiply by 2048
return n;
}
function iterate(secret, n) {
return Array.from({ length: n }).reduce((s) => process(s), secret);
}
function part1(input) {
return d3.sum(input.split("\n").map((n) => iterate(Number(n), 2000)));
}
function changeSequence(secret, n) {
const result = [];
let s = secret;
let prev = secret % 10;
for (let i = 0; i < n; i++) {
s = process(s);
result.push([s % 10, (s % 10) - prev]);
prev = s % 10;
}
return result;
}
function encodeSeq(seq) {
return (
(seq[0] + 9) * 6859 + (seq[1] + 9) * 361 + (seq[2] + 9) * 19 + (seq[3] + 9)
);
}
function part2(input) {
let seqPrices = new Map(); // Global map for all buyers
input.split("\n").forEach((secret) => {
const changes = changeSequence(Number(secret), 2000);
const monkeySeq = new Map(); // Map for each monkey
let seq4 = changes.slice(0, 4).map((d) => d[1]);
monkeySeq.set(encodeSeq(seq4), changes[3][0]);
for (let i = 4; i < changes.length; i++) {
seq4.push(changes[i][1]);
seq4.shift();
// If the sequence has already been matched for this monkey, skip it
const seqKey = encodeSeq(seq4);
if (!monkeySeq.has(seqKey)) {
monkeySeq.set(seqKey, changes[i][0]);
}
}
// Merge the current monkey's prices into the global prices
seqPrices = AOC.mergeMaps(seqPrices, monkeySeq);
});
return d3.max([...seqPrices.values()]);
}
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
