CF1256F Equalizing Two Strings

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.