PHONELST - 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.
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.
For each test case, output “YES” if the list is consistent, or “NO” otherwise.
Input: 2 3 911 97625999 91125426 5 113 12340 123440 12345 98346 Output: NO YES
Weak test cases. sorting solution must not pass.
First ever TRIE problem solved. No solutions seen, no excuses, only pure love :)
why even sort when a prime=150003 and a hash table can get the way.
1.Take care while sorting! Don't just directly use inbuilt sort function over strings.
I found python to be too slow for this problem. Solved using ditto algorithm in cpp. Got a WA due to a wild character being printed in output :|Last edit: 2017-05-01 10:28:03
My first try using trie :) Nice questions !! loved it !!
Prefer "Trie".Checking can be done at the time of insertion.Last edit: 2017-03-28 19:24:12
Note the difference between sorting of numbers and lexigraphically sorting the numbers taken as string :)
First solved via sorting, then via Tries. First problem on tries!
Solved using sorting..!! Will be back with Trie..!!