Equalizing Two Strings

### 题意 给你两长度都为 $n$ 的小写字符串 $S, T$。 每次操作中你可以任选一个 $L (1\le L\le n)$，同时翻转 $S$ 中的任意一个长度为 $L$ 的子串和 $T$ 中任意一个长度为 $L$ 的子串。 请回答你是否能在若干次操作后使两字符串一样？ ### 输入格式 第一行一个正整数 $q(1\le q\le 10^4)$ 表示询问次数 接下来 $q$ 组数据，每组数据三行，第一行一个正整数 $n(1\le n\le 2\times 10^5)$，第二行一个字符串 $S$，第三行一个字符串 $T$。 保证 $\sum n\le 2\times 10^5$ ### 输出格式 $q$ 行，每行一个字符串 ``YES`` 或 ``NO``。

You are given two strings $ s $ and $ t $ both of length $ n $ and both consisting of lowercase Latin letters. In one move, you can choose any length $ len $ from $ 1 $ to $ n $ and perform the following operation: - Choose any contiguous substring of the string $ s $ of length $ len $ and reverse it; - at the same time choose any contiguous substring of the string $ t $ of length $ len $ and reverse it as well. Note that during one move you reverse exactly one substring of the string $ s $ and exactly one substring of the string $ t $ . Also note that borders of substrings you reverse in $ s $ and in $ t $ can be different, the only restriction is that you reverse the substrings of equal length. For example, if $ len=3 $ and $ n=5 $ , you can reverse $ s[1 \dots 3] $ and $ t[3 \dots 5] $ , $ s[2 \dots 4] $ and $ t[2 \dots 4] $ , but not $ s[1 \dots 3] $ and $ t[1 \dots 2] $ . Your task is to say if it is possible to make strings $ s $ and $ t $ equal after some (possibly, empty) sequence of moves. You have to answer $ q $ independent test cases.

The first line of the input contains one integer $ q $ ( $ 1 \le q \le 10^4 $ ) — the number of test cases. Then $ q $ test cases follow. The first line of the test case contains one integer $ n $ ( $ 1 \le n \le 2 \cdot 10^5 $ ) — the length of $ s $ and $ t $ . The second line of the test case contains one string $ s $ consisting of $ n $ lowercase Latin letters. The third line of the test case contains one string $ t $ consisting of $ n $ lowercase Latin letters. It is guaranteed that the sum of $ n $ over all test cases does not exceed $ 2 \cdot 10^5 $ ( $ \sum n \le 2 \cdot 10^5 $ ).

For each test case, print the answer on it — "YES" (without quotes) if it is possible to make strings $ s $ and $ t $ equal after some (possibly, empty) sequence of moves and "NO" otherwise.

4
4
abcd
abdc
5
ababa
baaba
4
asdf
asdg
4
abcd
badc

NO
YES
NO
YES