题库练习 Arrays Sum
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A13701 | Arrays Sum

时间限制1s
内存限制256MB
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题目描述

You are given a non-decreasing array of non-negative integers $a_1, a_2, \ldots, a_n$ . Also you are given a positive integer $k$ .

You want to find $m$ non-decreasing arrays of non-negative integers $b_1, b_2, \ldots, b_m$ , such that:

- The size of $b_i$ is equal to $n$ for all $1 \leq i \leq m$ .
- For all $1 \leq j \leq n$ , $a_j = b_{1, j} + b_{2, j} + \ldots + b_{m, j}$ . In the other word, array $a$ is the sum of arrays $b_i$ .
- The number of different elements in the array $b_i$ is at most $k$ for all $1 \leq i \leq m$ .

Find the minimum possible value of $m$ , or report that there is no possible $m$ .

输入格式

The first line contains one integer $t$ ( $1 \leq t \leq 100$ ): the number of test cases.

The first line of each test case contains two integers $n$ , $k$ ( $1 \leq n \leq 100$ , $1 \leq k \leq n$ ).

The second line contains $n$ integers $a_1, a_2, \ldots, a_n$ ( $0 \leq a_1 \leq a_2 \leq \ldots \leq a_n \leq 100$ , $a_n > 0$ ).

输出格式

For each test case print a single integer: the minimum possible value of $m$ . If there is no such $m$ , print $-1$ .

输入输出样例

输入 #1
6
4 1
0 0 0 1
3 1
3 3 3
11 3
0 1 2 2 3 3 3 4 4 4 4
5 3
1 2 3 4 5
9 4
2 2 3 5 7 11 13 13 17
10 7
0 1 1 2 3 3 4 5 5 6
输出 #1
-1
1
2
2
2
1
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