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#841 - Keys and Rooms

Problem Description

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.

Solution

/**
 * @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;
};