Problem of the day
1. Room 0 is the only room that is initially unlocked and doesn’t require any key to enter.
2. Any other room can be visited only if you have the key to that room.
3. More than one room can have keys to the same room.
4. You are allowed to visit rooms in any order.
5. You can visit any room multiple times.
The first line contains an integer 'T', which denotes the total number of test cases or queries to be run. Then, the 'T' test cases follow.
The first line of every test case contains an integer 'N', denoting the number of rooms. Then 'N' lines follow.
Each line consists of 'M+1' space-separated integers. The first integer denotes the total number of keys present in this room. The next M integers denote the numbers of the corresponding rooms whose keys are present in this room.
Note that the i-th line denotes information about the keys present in the i-th room.
For more clarity, please refer to the sample inputs.
For each test case, return “True” if it is possible to visit each and every room, otherwise return “False” if it’s not possible.
You do not need to print anything. It has already been taken care of. Just implement the given function.
1 <= T <= 100
1 <= N <= 5000
1 <= M <= 50
0 <= keys[i] < N
Time Limit: 1sec
1
5
2 1 2
1 0
2 1 0
1 4
1 3
False
In the given example, room 0 has keys to room 1 and room 2. So we can go to room 1 and room 2 using these keys. But none of these two rooms has the keys to room 3 and room 4, so we can’t visit room 3 and room 4. Hence, the answer is False.
1
5
2 1 2
1 3
2 1 0
1 4
1 2
True
In the given example, room 0 has keys to room 1 and room 2. Room 1 has the key to room 3, and room 3 has the key to room 4. So we can visit each and every room. Hence, the answer is True.