SUBLEX - Lexicographical Substring Search
Little Daniel loves to play with strings! He always finds different ways to have fun with strings! Knowing that, his friend Kinan decided to test his skills so he gave him a string S and asked him Q questions of the form:
If all distinct substrings of string S were sorted lexicographically, which one will be the K-th smallest?
After knowing the huge number of questions Kinan will ask, Daniel figured out that he can't do this alone. Daniel, of course, knows your exceptional programming skills, so he asked you to write him a program which given S will answer Kinan's questions.
S = "aaa" (without quotes)
substrings of S are "a" , "a" , "a" , "aa" , "aa" , "aaa". The sorted list of substrings will be:
"a", "aa", "aaa".
In the first line there is Kinan's string S (with length no more than 90000 characters). It contains only small letters of English alphabet. The second line contains a single integer Q (Q <= 500) , the number of questions Daniel will be asked. In the next Q lines a single integer K is given (0 < K < 2^31).
Output consists of Q lines, the i-th contains a string which is the answer to the i-th asked question.
Edited: Some input file contains garbage at the end. Do not process them.
I got AC if I ignore the case that k >= (distinct substrings)...
My 150th :-)
output should be starting position and length of result string, not the whole result string.
Finally get AC with SAM!!!
SA can be O(nlogn+qlogq)
SAM is best
Suffice array with O(n * (logn)^2) is enough.
well...I got WA for lots of times when supposing there is possibility that the K would be larger than the#(distinct substrings)...But I got AC supposing it doesn't exist.....It is strange...
Suffix array nlog^2n with optimization, LCP, and binary search passed.