function parseRules(input) {
return new Map(
input.map((s) => {
const fields = s.match(/(.+): (\d+)-(\d+) or (\d+)-(\d+)/);
return [fields[1], fields.slice(2).map(Number)];
})
);
}
function invalidFields(ranges, ticket) {
const applyRules = (f) =>
ranges.every(
([mn1, mx1, mn2, mx2]) => (f < mn1 || f > mx1) && (f < mn2 || f > mx2)
);
return ticket.filter(applyRules);
}
function part1([ruleInput, tickets]) {
const ranges = [...parseRules(ruleInput).values()];
return AOC.sum(tickets.map((ticket) => invalidFields(ranges, ticket)).flat());
}
function validTickets(rules, tickets) {
const ranges = [...rules.values()];
return tickets.filter((ticket) => invalidFields(ranges, ticket).length == 0);
}
function satisfiedRules(n, rules) {
return new Set([
...new Map(
AOC.filterSet(
rules,
([_, [mn1, mx1, mn2, mx2]]) =>
(n >= mn1 && n <= mx1) || (n >= mn2 && n <= mx2)
)
).keys()
]);
}
function satisfiedAtPos(pos, rules, tickets) {
return AOC.intersections(tickets.map((ns) => satisfiedRules(ns[pos], rules)));
}
function rulesAtPositions(rules, tickets) {
return new Map(
AOC.range(0, tickets[0].length - 1).map((pos) => [
pos,
satisfiedAtPos(pos, rules, tickets)
])
);
}
function departurePositions(rules) {
return [...rules]
.filter(([k, _]) => k.startsWith("departure"))
.map(([_, v]) => v);
}
function depVals(ticket, depPos) {
return depPos.map((pos) => ticket[pos]);
}
function part2([ruleInput, myTicket, ticketInput]) {
const rules = parseRules(ruleInput);
const vTickets = validTickets(rules, ticketInput);
const fieldPositions = AOC.invertMap(
AOC.eliminate(rulesAtPositions(rules, vTickets))
);
return AOC.product(depVals(myTicket, departurePositions(fieldPositions)));
}
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.
