Codeforces Round 748 (Div. 3) |
---|
Finished |
A sequence of round and square brackets is given. You can change the sequence by performing the following operations:
The operations can be performed in any order any number of times.
You are given a string $$$s$$$ of the length $$$n$$$ and $$$q$$$ queries of the type "l r" where $$$1 \le l < r \le n$$$. For every substring $$$s[l \dots r]$$$, find the minimum cost to pay to make it a correct bracket sequence. It is guaranteed that the substring $$$s[l \dots r]$$$ has an even length.
The queries must be processed independently, i.e. the changes made in the string for the answer to a question $$$i$$$ don't affect the queries $$$j$$$ ($$$j > i$$$). In other words, for every query, the substring $$$s[l \dots r]$$$ is given from the initially given string $$$s$$$.
A correct bracket sequence is a sequence that can be built according the following rules:
E.g. the sequences "", "(()[])", "[()()]()" and "(())()" are correct bracket sequences whereas "(", "[(])" and ")))" are not.
The first line contains one integer $$$t$$$ ($$$1 \le t \le 100$$$) — the number of test cases. Then $$$t$$$ test cases follow.
For each test case, the first line contains a non-empty string $$$s$$$ containing only round ('(', ')') and square ('[', ']') brackets. The length of the string doesn't exceed $$$10^6$$$. The string contains at least $$$2$$$ characters.
The second line contains one integer $$$q$$$ ($$$1 \le q \le 2 \cdot 10^5$$$) — the number of queries.
Then $$$q$$$ lines follow, each of them contains two integers $$$l$$$ and $$$r$$$ ($$$1 \le l < r \le n$$$ where $$$n$$$ is the length of $$$s$$$). It is guaranteed that the substring $$$s[l \dots r]$$$ has even length.
It is guaranteed that the sum of the lengths of all strings given in all test cases doesn't exceed $$$10^6$$$. The sum of all $$$q$$$ given in all test cases doesn't exceed $$$2 \cdot 10^5$$$.
For each test case output in a separate line for each query one integer $$$x$$$ ($$$x \ge 0$$$) — the minimum cost to pay to make the given substring a correct bracket sequence.
3 ([))[)()][]] 3 1 12 4 9 3 6 )))))) 2 2 3 1 4 [] 1 1 2
0 2 1 0 0 0
Consider the first test case. The first query describes the whole given string, the string can be turned into the following correct bracket sequence: "([()])()[[]]". The forms of the brackets aren't changed so the cost of changing is $$$0$$$.
The second query describes the substring ")[)()]". It may be turned into "(()())", the cost is equal to $$$2$$$.
The third query describes the substring "))[)". It may be turned into "()()", the cost is equal to $$$1$$$.
The substrings of the second test case contain only round brackets. It's possible to prove that any sequence of round brackets having an even length may be turned into a correct bracket sequence for the cost of $$$0$$$ burles.
In the third test case, the single query describes the string "[]" that is already a correct bracket sequence.
Name |
---|