atcoder#AGC031A. [AGC031A] Colorful Subsequence
[AGC031A] Colorful Subsequence
Score : points
Problem Statement
You are given a string of length . Among its subsequences, count the ones such that all characters are different, modulo . Two subsequences are considered different if their characters come from different positions in the string, even if they are the same as strings.
Here, a subsequence of a string is a concatenation of one or more characters from the string without changing the order.
Constraints
- consists of lowercase English letters.
Input
Input is given from Standard Input in the following format:
Output
Print the number of the subsequences such that all characters are different, modulo .
4
abcd
15
Since all characters in itself are different, all its subsequences satisfy the condition.
3
baa
5
The answer is five: b
, two occurrences of a
, two occurrences of ba
. Note that we do not count baa
, since it contains two a
s.
5
abcab
17