Advent of Code 2023 - Day 20 - Part 1

const modulate = (module, pulse) => {
  switch (module.type) {
    case "b": {
      return pulse.value;
    }
    case "%": {
      if (pulse.value == HIGH_PULSE) {
        return null;
      }
      module.on = !module.on;
      return module.on ? HIGH_PULSE : LOW_PULSE;
    }
    case "&": {
      module.inputs[pulse.from] = pulse.value;
      for (const p of Object.values(module.inputs)) {
        if (p == LOW_PULSE) {
          return HIGH_PULSE;
        }
      }
      return LOW_PULSE;
    }
  }
  if (module.label == "broadcaster") {
    return pulse;
  }
};

const solvePart1 = (input) => {
  const modules = parse(input).modules;
  const cycles = 1_000;
  const counters = {
    low: 0,
    high: 0,
  };
  for (let i = 0; i < cycles; i++) {
    const pulses = [
      {
        from: "button",
        to: "broadcaster",
        value: LOW_PULSE,
      },
    ];
    while (pulses.length > 0) {
      const pulse = pulses.shift(); // FIFO
      counters[pulse.value]++;
      const module = modules[pulse.to];
      if (!module) {
        continue;
      }
      const newPulse = modulate(module, pulse);
      if (!newPulse) {
        continue;
      }
      for (const destination of module.destinations) {
        pulses.push({
          from: module.label,
          to: destination,
          value: newPulse,
        });
      }
    }
  }
  return counters.low * counters.high;
};