PHONELST - Phone List

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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
hrithox_2000: 2021-02-13 16:00:15

a good problem can be solved using a map and checking the node coming how many times in the trie tree

ti18padung: 2020-11-24 13:48:38

hurraay

navneet_01: 2020-10-29 10:38:52

If using trie without sorting
1.Also check if you are at the last index of any string,it should not have any child from that point.If there is any then it is inconsistent.
2.do check whether you marked the endpoint or not
3.not need to worry about leading zero or sorting

Last edit: 2020-10-29 10:39:09
robosapien: 2020-06-21 00:57:53

If you're getting WA with trie, try this
2
911
91
Output : NO

dmorgans: 2020-05-11 15:10:37

my 51st

ck_17: 2020-05-08 11:16:40

it will have leading zeros.

asanyal122: 2020-04-29 14:47:38

similar problem from hackerrank No Prefix Set.

manish_thakur: 2020-03-23 08:11:24

YAY, first tries question , good for learning

killer_knight: 2019-10-16 15:34:21

be careful with phone nos starting with zeros :)

sanket17: 2019-07-13 10:26:20

Brute force
Remember if you find prefix sequence then print "NO" it cost me 1WA


Added by:Andres Galvis
Date:2009-03-08
Time limit:1s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ERL JS-RHINO NODEJS PERL6 VB.NET
Resource:Nordic Collegiate Programming Contest 2007