时间限制;5000 ms | 内存限制;65536 KB
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 ? t ? 40, the number of test cases. Each test
, the number of phone numbers, on a separate line, 1 ? ? 10000. case starts with nn
Then follows n lines with one unique phone number on each line. A phone number is a
sequence of at most ten digits.
For each test case, output “YES” if the list is consistent, or “NO” otherwise.
Nordic Collegiate Programming Contest 2007