Time Limit: 2 Seconds
Memory Limit: 65536 KB
Let us define a regular brackets sequence in the following way:
1. Empty sequence is a regular sequence.
2. If S is a regular sequence, then (S) and [S] are both regular sequences.
3. If A and B are regular sequences, then AB is a regular sequence.
For example, all of the following sequences of characters are regular brackets
(), , (()), (), (), ()[()]
And all of the following character sequences are not:
(, [, ), )(, ([)], ([(]
Some sequence of characters '(', ')', '[', and ']' is given. You are to find
the shortest possible regular brackets sequence, that contains the given character
sequence as a subsequence. Here, a string a1 a2 ... an is called a subsequence
of the string b1 b2 ... bm, if there exist such indices 1 = i1 < i2 <
... < in = m, that aj = bij for all 1 = j = n.
The input file contains at most 100 brackets (characters '(', ')', '[' and ']')
that are situated on a single line without any other characters among them.
Write to the output file a single line that contains some regular brackets sequence
that has the minimal possible length and contains the given sequence as a subsequence.
This problem contains multiple test cases!
The first line of a multiple input is an integer N, then a blank line followed
by N input blocks. Each input block is in the format indicated in the problem
description. There is a blank line between input blocks.
The output format consists of N output blocks. There is a blank line between
Source: Northeastern Europe 2001