CF1730D Prefixes and Suffixes

You have two strings $ s_1 $ and $ s_2 $ of length $ n $ , consisting of lowercase English letters. You can perform the following operation any (possibly zero) number of times: - Choose a positive integer $ 1 \leq k \leq n $ . - Swap the prefix of the string $ s_1 $ and the suffix of the string $ s_2 $ of length $ k $ . Is it possible to make these two strings equal by doing described operations?

The first line contains a single integer $ t $ ( $ 1 \le t \le 10^4 $ ) — the number of test cases. Then the test cases follow. Each test case consists of three lines. The first line contains a single integer $ n $ ( $ 1 \le n \le 10^5 $ ) — the length of the strings $ s_1 $ and $ s_2 $ . The second line contains the string $ s_1 $ of length $ n $ , consisting of lowercase English letters. The third line contains the string $ s_2 $ of length $ n $ , consisting of lowercase English letters. It is guaranteed that the sum of $ n $ for all test cases does not exceed $ 2 \cdot 10^5 $ .

For each test case, print "YES" if it is possible to make the strings equal, and "NO" otherwise.

In the first test case: - Initially $ s_1 = \mathtt{cbc} $ , $ s_2 = \mathtt{aba} $ . - Operation with $ k = 1 $ , after the operation $ s_1 = \mathtt{abc} $ , $ s_2 = \mathtt{abc} $ . In the second test case: - Initially $ s_1 = \mathtt{abcaa} $ , $ s_2 = \mathtt{cbabb} $ . - Operation with $ k = 2 $ , after the operation $ s_1 = \mathtt{bbcaa} $ , $ s_2 = \mathtt{cbaab} $ . - Operation with $ k = 3 $ , after the operation $ s_1 = \mathtt{aabaa} $ , $ s_2 = \mathtt{cbbbc} $ . - Operation with $ k = 1 $ , after the operation $ s_1 = \mathtt{cabaa} $ , $ s_2 = \mathtt{cbbba} $ . - Operation with $ k = 2 $ , after the operation $ s_1 = \mathtt{babaa} $ , $ s_2 = \mathtt{cbbca} $ . - Operation with $ k = 1 $ , after the operation $ s_1 = \mathtt{aabaa} $ , $ s_2 = \mathtt{cbbcb} $ . - Operation with $ k = 2 $ , after the operation $ s_1 = \mathtt{cbbaa} $ , $ s_2 = \mathtt{cbbaa} $ . In the third test case, it's impossible to make strings equal.