题目描述
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?
Input
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 $2 \cdot 10^5$.
Output
For each test case, print "YES" if it is possible to make the strings equal, and "NO" otherwise.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
样例输出
提示
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.