PHONELST  Phone List
Phone List
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:
 Emergency 911
 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.
Input
The first line of input gives a single integer, 1 <= t <= 40, the number of test cases. Each test case starts with n, the number of phone numbers, on a separate line, 1 <= n <= 10000. Then follows n lines with one unique phone number on each line. A phone number is a sequence of at most ten digits.
Output
For each test case, output “YES” if the list is consistent, or “NO” otherwise.
Example
Input: 2 3 911 97625999 91125426 5 113 12340 123440 12345 98346 Output: NO YES
hide comments
Mohannad Abdullah Hassan:
20100619 11:54:12
Can any number start with a zero? 

vaibhav paliwal:
20090723 07:22:21
no 

madhav:
20090629 22:34:28
are there any spaces b/w the digits of the phone number?? 
Added by:  Andres Galvis 
Date:  20090308 
Time limit:  1s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ERL JSRHINO NODEJS PERL6 VB.NET 
Resource:  Nordic Collegiate Programming Contest 2007 