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.