solutions/0841-keys-and-rooms.js

/**
 * 841. Keys and Rooms
 * https://leetcode.com/problems/keys-and-rooms/
 * Difficulty: Medium
 *
 * There are n rooms labeled from 0 to n - 1 and all the rooms are locked except for room 0.
 * Your goal is to visit all the rooms. However, you cannot enter a locked room without
 * having its key.
 *
 * When you visit a room, you may find a set of distinct keys in it. Each key has a number
 * on it, denoting which room it unlocks, and you can take all of them with you to unlock
 * the other rooms.
 *
 * Given an array rooms where rooms[i] is the set of keys that you can obtain if you visited
 * room i, return true if you can visit all the rooms, or false otherwise.
 */

/**
 * @param {number[][]} rooms
 * @return {boolean}
 */
var canVisitAllRooms = function(rooms) {
  const set = new Set([0]);
  for (const key of set) {
    rooms[key].forEach(value => set.add(value));
  }
  return set.size === rooms.length;
};