Codeforces Round 649 (Div. 2)
A
XXXXX
Codeforces
1200
原题
←B →
翻译中…

Ehab loves number theory, but for some reason he hates the number $x$. Given an array $a$, find the length of its longest subarray such that the sum of its elements isn't divisible by $x$, or determine that such subarray doesn't exist.

翻译中…

An array $a$ is a subarray of an array $b$ if $a$ can be obtained from $b$ by deletion of several (possibly, zero or all) elements from the beginning and several (possibly, zero or all) elements from the end.

翻译中…

Input

翻译中…

The first line contains an integer $t$ $(1 \le t \le 5)$ — the number of test cases you need to solve. The description of the test cases follows.

翻译中…

The first line of each test case contains 2 integers $n$ and $x$ ($1 \le n \le 10^5$, $1 \le x \le 10^4$) — the number of elements in the array $a$ and the number that Ehab hates.

翻译中…

The second line contains $n$ space-separated integers $a_1$, $a_2$, $\ldots$, $a_{n}$ ($0 \le a_i \le 10^4$) — the elements of the array $a$.

翻译中…

Output

翻译中…

For each testcase, print the length of the longest subarray whose sum isn't divisible by $x$. If there's no such subarray, print $-1$.

翻译中…

Note

翻译中…

In the first test case, the subarray $[2,3]$ has sum of elements $5$, which isn't divisible by $3$.

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In the second test case, the sum of elements of the whole array is $6$, which isn't divisible by $4$.

翻译中…

In the third test case, all subarrays have an even sum, so the answer is $-1$.

翻译中…

样例

Input #1
3
3 3
1 2 3
3 4
1 2 3
2 2
0 6
Output #1
2
3
-1
InputCopy OutputCopy
题目信息
题号
1364A
时间限制
1 s
内存限制
256 MB
标签
暴力
数据结构
数论
双指针

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。