advent-of-code-2024/day5/part1.ts
2024-12-08 01:12:44 -07:00

27 lines
944 B
TypeScript

export async function solve() {
const [rules, pages] = await Deno.readTextFile(import.meta.dirname + "/input.txt")
.then(i => i
.split("\n\n")
).then(([rules, pages]) => [
rules.split("\n").map(e => e.split("|") as [string, string]),
pages.split("\n").map(e => e.split(","))
] as const);
let sum = 0;
for (const pageGroup of pages) {
let valid = true;
for (let i = 1; i < pageGroup.length; i++) {
const matchingRules = rules.filter(([before, _]) => before == pageGroup[i]).filter(
([before, _]) => before == pageGroup[i]
).map(([_, after]) => after);
if (matchingRules.some(after => pageGroup.slice(0, i).includes(after))) {
valid = false;
break
}
}
if (valid) sum += +pageGroup[Math.floor(pageGroup.length / 2)];
}
return sum
}