AoC-2017-day13.js

const input = require("fs").readFileSync("day13-input.txt", "UTF-8");

function cycle() {
  keys = Object.keys(map);
  keys.forEach(key => {
    up = map[key]["up"];
    depth = map[key]["length"];
    if (up) {
      map[key]["state"] += 1;
      if (map[key]["state"] == depth - 1) {
        map[key]["up"] = false;
      }
    } else {
      map[key]["state"] -= 1;
      if (map[key]["state"] === 0) {
        map[key]["up"] = true;
      }
    }
  });
}

function part1() {
  map = {};
  input.split("\n").forEach(row => {
    split = row.split(": ");
    map[split[0]] = {
      state: 0,
      length: parseInt(split[1]),
      up: true
    };
  });
  keys = Object.keys(map).map(n => parseInt(n));
  min = Math.min(...keys);
  max = Math.max(...keys);
  hits = [];
  for (let i = 0; i <= max; i++) {
    key = String(i);
    if (typeof map[key] !== "undefined" && map[key]["state"] === 0) {
      hits.push(key);
    }
    cycle();
  }
  severity = hits.reduce((count, key) => {
    return count + parseInt(key) * map[key]["length"];
  }, 0);

  return severity;
}

function part2() {
  map = {};
  input.split("\n").forEach(row => {
    split = row.split(": ");
    map[split[0]] = {
      state: 0,
      length: parseInt(split[1]),
      up: true
    };
  });
  keys = Object.keys(map).map(n => parseInt(n));
  min = Math.min(...keys);
  max = Math.max(...keys);

  progress = 0;
  safeMap = { ...map };
  lastDelay = 0;
  while (progress < max + 1) {
    key = String(progress);
    if (
      typeof map[key] === "undefined" ||
      (typeof map[key] !== "undefined" && map[key]["state"] !== 0)
    ) {
      progress++;
    } else {
      progress = 0;
      map = { ...safeMap };
      cycle();
      safeMap = JSON.parse(JSON.stringify(map));
      lastDelay++;
    }
    cycle();
  }
  return lastDelay + 1;
}

console.log("Part 1:", part1());
console.log("Part 2:", part2());