Given a list of phone numbers, determine if it is consistent
in the sense that no number is the prefix of another. Let’s say
the phone catalogue listed these numbers:
Alice 97 625 999
Bob 91 12 54 26
In this case, it’s not possible to call Bob, because the
central would direct your call to the emergency line as soon as
you had dialled the first three digits of Bob’s phone number.
So this list would not be consistent.
The first line of input gives a single integer, $1 \le t \le 40$, the number of test
cases. Each test case starts with $n$, the number of phone numbers, on a
separate line, $1 \leq n \leq
10\, 000$. Then follows $n$ lines with one unique phone number
on each line. A phone number is a sequence of at most ten
digits. Note that leading zeros in phone numbers are
significant, e.g., “0911” is a different phone number than
For each test case, output “YES” if the list is consistent,
or “NO” otherwise.
|Sample Input 1
||Sample Output 1