Compute the total length of a string after repeatedly applying a character transformation rule for a fixed number of rounds.
You are given a string consisting of lowercase English letters and an integer .
In one transformation round, every character in the string is replaced according to a fixed rule. The exact replacement rule depends on the character, but the important property is that each round can increase the total number of characters.
Your task is to determine the total number of characters in the string after applying the transformation exactly times.
Because the answer can become very large, return it modulo .
Design an efficient algorithm that avoids explicitly constructing the transformed string when is large.
s.t representing the number of transformation rounds.The exact per-character replacement rule is assumed to be provided by the problem’s transformation specification.
t transformations, modulo .Example 1
Input
s = "ab" t = 2
Output
4
Explanation
After applying the transformation rule twice, the string contains 4 characters in total.
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