Codeforces Round 882 (Div. 2)
C
Vampiric Powers, anyone?
Codeforces
1400
原题
← BD →
翻译中…

DIO knows that the Stardust Crusaders have determined his location and will be coming to fight him. To foil their plans he decides to send out some Stand users to fight them. Initially, he summoned $n$ Stand users with him, the $i$-th one having a strength of $a_i$. Using his vampiric powers, he can do the following as many times as he wishes:

翻译中…
  • Let the current number of Stand users be $m$.
  • DIO chooses an index $i$ ($1 \le i \le m$).
  • Then he summons a new Stand user, with index $m+1$ and strength given by: $$a_{m+1} = a_i \oplus a_{i+1} \oplus \ldots \oplus a_m,$$where the operator $\oplus$ denotes the bitwise XOR operation.
  • Now, the number of Stand users becomes $m+1$.
翻译中…

Unfortunately for DIO, by using Hermit Purple's divination powers, the Crusaders know that he is plotting this, and they also know the strengths of the original Stand users. Help the Crusaders find the maximum possible strength of a Stand user among all possible ways that DIO can summon.

翻译中…

Input

翻译中…

Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10\,000$). The description of the test cases follows.

翻译中…

The first line of each test case contains a single integer $n$ ($1 \le n \le 10^5$)  – the number of Stand users initially summoned.

翻译中…

The second line of each test case contains $n$ integers $a_1, a_2, \ldots, a_n$ ($0 \le a_i \lt 2^8$)  – the strength of each Stand user.

翻译中…

It is guaranteed that the sum of $n$ over all test cases does not exceed $10^5$.

翻译中…

Output

翻译中…

For each test case, output a single integer, maximum strength of a Stand user among all possible ways that DIO can summon.

翻译中…

Note

翻译中…

In the first test case, one of the ways to add new Stand users is as follows:

翻译中…
  • Choose $i=n$. Now, $a$ becomes $[0,2,5,1,1]$.
  • Choose $i=1$. Now, $a$ becomes $[0,2,5,1,1,7]$. $7$ is the maximum strength of a Stand user DIO can summon.
翻译中…

In the second test case, DIO does not need to add more Stand users because $3$ is the maximum strength of a Stand user DIO can summon.

翻译中…

样例

Input #1
3
4
0 2 5 1
3
1 2 3
5
8 2 4 12 1
Output #1
7
3
14
InputCopy OutputCopy
题目信息
题号
1847C
时间限制
1 s
内存限制
256 MB
标签
位运算
暴力
动态规划
贪心

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。