|시간 제한||메모리 제한||제출||정답||맞은 사람||정답 비율|
|1 초||128 MB||18||6||6||66.667%|
We give the following inductive definition of a “regular brackets” sequence:
For instance, all of the following character sequences are regular brackets sequences:
(), , (()), (), ()[()]
while the following character sequences are not:
(, ], )(, ([)], ([(]
Given a brackets sequence of characters a1a2...an, your goal is to find the length of the longest regular brackets sequence that is a subsequence of s. That is, you wish to find the largest m such that for indices i1, i2, . . . , im where 1 ≤ i1 < i2 < . . . < im ≤ n, ai1 ai2 . . . aim is a regular brackets sequence.
The input test file will contain multiple test cases. Each input test case consists of a single line containing only the characters (, ), [, and ]; each input test will have length between 1 and 100, inclusive. The end-of-file is marked by a line containing the word “end” and should not be processed.
For each input case, the program should print the length of the longest possible regular brackets subsequence on a single line.
((())) ()()() (]) )[)( ([) end
6 6 4 0 6
Given the initial sequence ([(])], the longest regular brackets subsequence is [()].