AtCoder Grand Contest 074
翻译中…
Problem Statement
翻译中…
For a string $X = X_1X_2\dots X_{|X|}$ and positive integers $l,r~(1 \leq l \leq r \leq |X|)$, let $X_{l,r} = X_l X_{l+1}\dots X_r$.
翻译中…
You are given a string $S=S_1S_2\dots S_{|S|}$ consisting of A and B.
You are given $Q$ queries. For each query, answer the following question:
翻译中…
- Starting from the state
$T = S_{l,r}$, find the minimum possible length of a palindrome that can be obtained by performing the operation "choose one occurrence ofABthat appears as a contiguous substring in$T$and delete it" zero or more times. If no palindrome can be obtained regardless of how the operation is performed, output-1.
翻译中…
Constraints
翻译中…
$1 \leq |S| \leq 4 \times 10^5$$1 \leq Q \leq 5 \times 10^4$$1 \leq l \leq r \leq |S|$$S$is a string consisting ofAandB.$Q,l,r$are integers.
翻译中…
Input
翻译中…
The input is given from Standard Input in the following format:
翻译中…
S
Q
\mathrm{Query}_1
\mathrm{Query}_2
\vdots
\mathrm{Query}_Q
翻译中…
$\mathrm{Query}_q$ represents the $q$-th query and is given in the following format:
翻译中…
l r
翻译中…
Output
翻译中…
Output $Q$ lines. The $q$-th line should contain the answer for $\mathrm{Query}_q$.
翻译中…
样例
Input #1
ABBABB
5
1 6
4 5
3 5
2 3
3 4
Output #1
2
0
1
2
-1
For the first, second, and third queries, by performing the operation as follows, you can obtain a palindrome with the minimum length among those obtained by the operation.
- `ABBABB` $\rightarrow$ `ABBB` $\rightarrow$ `BB`
- `AB` $\rightarrow$ (empty string)
- `BAB` $\rightarrow$ `B`
题目信息
题面与样例版权归 AtCoder 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。