adventofcode2023/day6/day6-ts.ts

type Race = {
  time: number;
  distance: number;
};
const races: Race[] = [];

const timeFrom = new Date().getTime();

// const input = `Time:        47     70     75     66
// Distance:   282   1079   1147   1062`.split("\n");

const input = `Time:        47707566
Distance:   282107911471062`.split("\n");

// parse input
const [t, ...rtimes] = input[0].split(" ");
const times = rtimes.filter((o) => o !== "").map((o) => Number(o));
const [d, ...rdist] = input[1].split(" ");
const dist = rdist.filter((o) => o !== "").map((o) => Number(o));

for (let i = 0; i < times.length; i++) {
  races.push({ time: times[i], distance: dist[i] });
}
console.log(races);

function getSpeed(race: Race, holdTime: number): number {
  return (race.time - holdTime) * holdTime;
}

const counts: number[] = [];

for (const race of races) {
  let from = 1;
  let to = 1;
  for (let i = 0; i < race.time; i++) {
    if (getSpeed(race, i) > race.distance) {
      from = i;
      break;
    }
  }
  for (let i = race.time; i >= 0; i--) {
    if (getSpeed(race, i) > race.distance) {
      to = i;
      break;
    }
  }
  counts.push(to - from + 1);

}

let mul = 1;
for (const count of counts) {
  mul *= count;
}
console.log(mul);

const timeTotal = new Date().getTime() - timeFrom;
console.log(`Time took: ${timeTotal}ms`);