LeetCode 841. Keys and Rooms - Python

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.

[@maged_helmy]

Code:
def canVisitAllRooms(self, rooms: List[List[int]]) -> bool:


stack = [0]
seen = set(stack)

while stack:
idx = stack.pop()

for j in rooms[idx]:
if j not in seen:
stack.append(j)
seen.add(j)

return len(seen) == len(rooms)

[@omarabdelkader5214]

thanks for this great illustration