Codeforces Round 708 (Div. 2)
B
M-arrays
Codeforces
1200
原题
← AC1 →
翻译中…

You are given an array $a_1, a_2, \ldots, a_n$ consisting of $n$ positive integers and a positive integer $m$.

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You should divide elements of this array into some arrays. You can order the elements in the new arrays as you want.

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Let's call an array $m$-divisible if for each two adjacent numbers in the array (two numbers on the positions $i$ and $i+1$ are called adjacent for each $i$) their sum is divisible by $m$. An array of one element is $m$-divisible.

翻译中…

Find the smallest number of $m$-divisible arrays that $a_1, a_2, \ldots, a_n$ is possible to divide into.

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Input

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The first line contains a single integer $t$ $(1 \le t \le 1000)$  — the number of test cases.

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The first line of each test case contains two integers $n$, $m$ $(1 \le n \le 10^5, 1 \le m \le 10^5)$.

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The second line of each test case contains $n$ integers $a_1, a_2, \ldots, a_n$ $(1 \le a_i \le 10^9)$.

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

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Output

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For each test case print the answer to the problem.

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Note

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In the first test case we can divide the elements as follows:

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  • $[4, 8]$. It is a $4$-divisible array because $4+8$ is divisible by $4$.
  • $[2, 6, 2]$. It is a $4$-divisible array because $2+6$ and $6+2$ are divisible by $4$.
  • $[9]$. It is a $4$-divisible array because it consists of one element.
翻译中…

样例

Input #1
4
6 4
2 2 8 6 9 4
10 8
1 1 1 5 2 4 4 8 6 7
1 1
666
2 2
2 4
Output #1
3
6
1
1
InputCopy OutputCopy
题目信息
题号
1497B
时间限制
1 s
内存限制
256 MB
标签
构造
贪心
数学

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。