Advent of Code 2023 - Day 19 - Part 2

class Node {
  /**
   * line: "in{s<1351:px,qqz}"
   * ranges: {
   *  x: {min: 1, max: 4000},
   *  m: {min: 1, max: 4000},
   *  a: {min: 1, max: 4000},
   *  s: {min: 1, max: 4000},
   * }
   */
  constructor(workflows, label, ranges) {
    this.ranges = ranges;
    this.label = label;
    this.children = [];
    const rules = workflows[label];

    let remainingRanges = JSON.parse(JSON.stringify(ranges));
    if (rules) {
      for (const rule of rules) {
        const newRanges = JSON.parse(JSON.stringify(remainingRanges));
        remainingRanges = JSON.parse(JSON.stringify(newRanges));
        if (rule.condition) {
          if (rule.condition == "<") {
            newRanges[rule.category].max = Math.max(newRanges[rule.category].min, rule.value - 1);
            remainingRanges[rule.category].min = newRanges[rule.category].max + 1;
          } else {
            newRanges[rule.category].min = Math.min(newRanges[rule.category].max, rule.value + 1);
            remainingRanges[rule.category].max = newRanges[rule.category].min - 1;
          }
        }
        this.children.push(new Node(workflows, rule.next, newRanges));
      }
    }
  }

  children() {
    return this.children;
  }
  total() {
    if (this.label == "R") {
      return 0;
    }
    if (this.label == "A") {
      return Object.keys(this.ranges).reduce((total, key) => {
        return total * (this.ranges[key].max - this.ranges[key].min + 1);
      }, 1);
    }
    return this.children.reduce((sum, child) => sum + child.total(), 0);
  }
}
const solvePart2 = (input) => {
  const data = parse(input);
  const ranges = {
    x: { min: 1, max: 4000 },
    m: { min: 1, max: 4000 },
    a: { min: 1, max: 4000 },
    s: { min: 1, max: 4000 },
  };
  const root = new Node(data.workflows, "in", ranges);
  return root.total();
};