Problem E
Even Substrings
You are given a string $s[1..n]$ consisting of the first $6$ lowercase English letters between a and f. A substring is called even if every distinct letter in it appears an even number of times. For example, in abbacac there are $4$ even substrings: abba, bb, acac, bbacac. If a same substring appears at different locations, they shall be counted multiple times, e.g. the string aaa has $2$ even substrings aa.
You are to process $q$ queries of the following two types:
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Given a range specified by two integers $l$ and $r$, count the number of even substrings in $s[l..r]$, the substring of $s$ starting at $s[l]$ and ending at $s[r]$ (both ends are inclusive).
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Given an index $i$ and a letter $x$ between a and f, change $s[i]$ to $x$.
Input
The first line of input has a single string $s[1..n]$ ($1 \leq n \leq 2 \cdot 10^5$) consisting of letters between a and f.
The second line of input has a single integer $q$ ($1 \leq q \leq 2 \cdot 10^5$), the number of queries. Each of the next $q$ lines gives one query:
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Type $1$ query has $1~ l~ r$ ($1 \leq l \leq r \leq n$).
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Type $2$ query has $2~ i~ x$ ($1 \leq i \leq n$), where $x$ is a letter between a and f.
There is at least one query of type $1$.
Output
For each type $1$ query output the number of even substrings on a single line.
Sample Input 1 | Sample Output 1 |
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abbacac 8 1 1 7 2 5 a 1 4 6 1 1 7 2 6 b 1 2 6 1 5 7 1 1 1 |
4 2 6 4 0 0 |