A1326.[COCI-2007_2008-contest1]#6 ZAPIS
省选/NOI-
通过率:0%
时间限制:1.00s
内存限制:128MB
题目描述
A regular bracket-sequence is a string of characters consisting only of opening and closing brackets, and satisfying the following conditions:
• An empty string is a regular bracket-sequence.
• If A is a regular bracket-sequence, then (A), [A] and {A} are also regular bracket-sequences.
• If A and B are regular bracket-sequences, then AB is also a regular bracket-sequence.
For example, the sequences [({})], {} i {}[{}] are regular, but the sequences [({{([, } and [{}])([{}] are not.
Ivica has found a string which looks like it could be a regular bracket-sequence. Some of the characters have become smudged and illegible, and could have been any character.
Write a program that calculates how many ways the illegible characters in the string can be replaced by brackets so that the result is a regular bracket-sequence. This number can be very large, so output only its last 5 digits.
输入格式
The first line contains an even integer N (2 ≤ N ≤ 200), the length of the string.
The second line contains the string. Illegible characters are represented by the '?' character.
输出格式
Output the number of regular bracket-sequences the string could have read.
输入输出样例
输入#1
6 ()()()
输出#1
1
输入#2
10 (?([?)]?}?
输出#2
3
输入#3
16 ???[???????]????
输出#3
92202
说明/提示
In the second example, the three matching regular bracket-sequences are ({([()])}), ()([()]{})
and ([([])]{}).