The World Is Just a Programming Task (Easy Version)

题意翻译

有一个括号序列，你可以选择两个位置i，j（i可以等于j），进行交换。使得最后的循环位置（i的数目）最大。 循环位置：i（0<=i<len），将前i个字符移到最后，得到的新序列是合法的括号序列。 - )()()( 的循环位置有 1、3、5 - )((()))( 的循环位置有 1、7

题目描述

This is an easier version of the problem. In this version, $ n \le 500 $ . Vasya is an experienced developer of programming competitions' problems. As all great minds at some time, Vasya faced a creative crisis. To improve the situation, Petya gifted him a string consisting of opening and closing brackets only. Petya believes, that the beauty of the bracket string is a number of its cyclical shifts, which form a correct bracket sequence. To digress from his problems, Vasya decided to select two positions of the string (not necessarily distinct) and swap characters located at this positions with each other. Vasya will apply this operation exactly once. He is curious what is the maximum possible beauty he can achieve this way. Please help him. We remind that bracket sequence $ s $ is called correct if: - $ s $ is empty; - $ s $ is equal to "( $ t $ )", where $ t $ is correct bracket sequence; - $ s $ is equal to $ t_1 t_2 $ , i.e. concatenation of $ t_1 $ and $ t_2 $ , where $ t_1 $ and $ t_2 $ are correct bracket sequences. For example, "(()())", "()" are correct, while ")(" and "())" are not. The cyclical shift of the string $ s $ of length $ n $ by $ k $ ( $ 0 \leq k < n $ ) is a string formed by a concatenation of the last $ k $ symbols of the string $ s $ with the first $ n - k $ symbols of string $ s $ . For example, the cyclical shift of string "(())()" by $ 2 $ equals "()(())". Cyclical shifts $ i $ and $ j $ are considered different, if $ i \ne j $ .

输入输出格式

输入格式

The first line contains an integer $ n $ ( $ 1 \le n \le 500 $ ), the length of the string. The second line contains a string, consisting of exactly $ n $ characters, where each of the characters is either "(" or ")".

输出格式

The first line should contain a single integer — the largest beauty of the string, which can be achieved by swapping some two characters. The second line should contain integers $ l $ and $ r $ ( $ 1 \leq l, r \leq n $ ) — the indices of two characters, which should be swapped in order to maximize the string's beauty. In case there are several possible swaps, print any of them.

输入输出样例

输入样例 #1

10
()()())(()

输出样例 #1

5
8 7

输入样例 #2

12
)(()(()())()

输出样例 #2

4
5 10

输入样例 #3

6
)))(()

输出样例 #3

0
1 1

说明

In the first example, we can swap $ 7 $ -th and $ 8 $ -th character, obtaining a string "()()()()()". The cyclical shifts by $ 0, 2, 4, 6, 8 $ of this string form a correct bracket sequence. In the second example, after swapping $ 5 $ -th and $ 10 $ -th character, we obtain a string ")(())()()(()". The cyclical shifts by $ 11, 7, 5, 3 $ of this string form a correct bracket sequence. In the third example, swap of any two brackets results in $ 0 $ cyclical shifts being correct bracket sequences.