311106: CF1935A. Entertainment in MAC
Description
Congratulations, you have been accepted to the Master's Assistance Center! However, you were extremely bored in class and got tired of doing nothing, so you came up with a game for yourself.
You are given a string $s$ and an even integer $n$. There are two types of operations that you can apply to it:
- Add the reversed string $s$ to the end of the string $s$ (for example, if $s = $ cpm, then after applying the operation $s = $ cpmmpc).
- Reverse the current string $s$ (for example, if $s = $ cpm, then after applying the operation $s = $ mpc).
It is required to determine the lexicographically smallest$^{\dagger}$ string that can be obtained after applying exactly $n$ operations. Note that you can apply operations of different types in any order, but you must apply exactly $n$ operations in total.
$^{\dagger}$A string $a$ is lexicographically smaller than a string $b$ if and only if one of the following holds:
- $a$ is a prefix of $b$, but $a \ne b$;
- in the first position where $a$ and $b$ differ, the string $a$ has a letter that appears earlier in the alphabet than the corresponding letter in $b$.
Each test consists of multiple test cases. The first line contains a single integer $t$ ($1 \leq t \leq 500$) — the number of test cases. The description of the test cases follows.
The first line of each test case contains a single even integer $n$ ($2 \leq n \leq 10^9$) — the number of operations applied to the string $s$.
The second line of each test case contains a single string $s$ ($1 \leq |s| \leq 100$), consisting of lowercase English letters, — the string to which the operations are applied.
OutputFor each test case, output a single line — the lexicographically smallest string that can be obtained after applying exactly $n$ operations.
ExampleInput5 4 cpm 2 grib 10 kupitimilablodarbuz 1000000000 capybara 6 abacabaOutput
cpm birggrib kupitimilablodarbuz arabypaccapybara abacabaNote
In the first test case, you can apply the operation of the second type (i.e., reverse the string $s$) $4$ times. Then the string $s$ will remain equal to cpm.
In the second test case, you can do the following:
- Apply the operation of the second type, after which $s$ will become equal to birg.
- Apply operation of the first type (i.e., add the reversed string $s$ to the end of the string $s$), after which $s$ will become equal to birggrib.
Output
你已经被大师助手中心录取了！然而，你在课堂上非常无聊，厌倦了无所事事，所以你想出了一个游戏。
给你一个字符串s和一个偶数整数n。你可以对其应用两种类型的操作：
1. 将字符串s的反向s添加到字符串s的末尾（例如，如果s = cpm，则应用操作后s = cpmmpc）。
2. 反转当前字符串s（例如，如果s = cpm，则应用操作后s = mpc）。
需要确定在应用正好n个操作后，可以获得字典序最小的字符串。注意，你可以按任何顺序应用不同类型的操作，但你必须总共应用正好n个操作。
输入输出数据格式：
输入：
第一行包含一个整数t（1≤t≤500）——测试用例的数量。
每个测试用例的第一行包含一个偶数整数n（2≤n≤10^9）——应用于字符串s的操作数。
每个测试用例的第二行包含一个由小写英文字母组成的字符串s（1≤|s|≤100），——要对其应用操作的字符串。
输出：
对于每个测试用例，输出一行——在应用正好n个操作后可以获得的最小字典序字符串。题目大意： 你已经被大师助手中心录取了！然而，你在课堂上非常无聊，厌倦了无所事事，所以你想出了一个游戏。 给你一个字符串s和一个偶数整数n。你可以对其应用两种类型的操作： 1. 将字符串s的反向s添加到字符串s的末尾（例如，如果s = cpm，则应用操作后s = cpmmpc）。 2. 反转当前字符串s（例如，如果s = cpm，则应用操作后s = mpc）。 需要确定在应用正好n个操作后，可以获得字典序最小的字符串。注意，你可以按任何顺序应用不同类型的操作，但你必须总共应用正好n个操作。 输入输出数据格式： 输入： 第一行包含一个整数t（1≤t≤500）——测试用例的数量。 每个测试用例的第一行包含一个偶数整数n（2≤n≤10^9）——应用于字符串s的操作数。 每个测试用例的第二行包含一个由小写英文字母组成的字符串s（1≤|s|≤100），——要对其应用操作的字符串。 输出： 对于每个测试用例，输出一行——在应用正好n个操作后可以获得的最小字典序字符串。