Editorial for Appleby Contest '20 P3 - Ridiculous String
Remember to use this editorial only when stuck, and not to copy-paste code from it. Please be respectful to the problem author and editorialist.
Submitting an official solution before solving the problem yourself is a bannable offence.
Submitting an official solution before solving the problem yourself is a bannable offence.
Author:
Subtask 1
The answer is always .
Time Complexity:
Subtask 2
If an answer exists, the prefix of the subsequence of equal to
must contain at least one character from each copy of
. Thus, we can just copy
times and check that instead.
Time Complexity:
Memory Complexity:
Subtask 3
The solution is the same as the previous subtask except you don't explicitly copy .
Time Complexity:
Memory Complexity:
Subtask 4
Construct an array where
contains the first index of the letter
in
with an index
. This array can be used to find the smallest prefix in
time.
Time Complexity:
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