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CF2078A.Final Verdict
Final Verdict
Testify - void (Mournfinale) feat. 星熊南巫
You are given an array of length , and must perform the following operation until the length of becomes .
Choose a positive integer such that is an integer. Split into subsequences such that:
- Each element of belongs to exactly one subsequence.
- The length of every subsequence is equal.
After this, replace $a = \left[ \operatorname{avg}(s_1), \operatorname{avg}(s_2), \ldots, \operatorname{avg}(s_k) \right]$, where $\operatorname{avg}(s) = \frac{ um_{i = 1}^{|s|} s_i}{|s|}$ is the average of all the values in the subsequence. For example, $\operatorname{avg}([1, 2, 1, 1]) = \frac{5}{4} = 1.25$.
Your task is to determine whether there exists a sequence of operations such that after all operations, .
A sequence is a subsequence of a sequence if can be obtained from by the deletion of several (possibly, zero or all) elements.
Input
Each test contains multiple test cases. The first line contains the number of test cases (). The description of the test cases follows.
The first line of each test case contains two integers , () — the length of the array and the final desired value.
The second line contains integers () — the array .
Output
For each test case, output "YES'" (without quotes) if there exists such a sequence of operations, and "NO" (without quotes) otherwise.
You can output "YES" and "NO" in any case (for example, strings "yES", "yes" and "Yes" will be recognized as a positive response).
Note
In the first test case, and already holds.
In the second test case, , and there exists no sequence of operations such that after all operations, .
In the third test case, , and here is one possible sequence of operations.
- , and . Hence, $a = [\operatorname{avg}(s_1), \operatorname{avg}(s_2)] = [7, 11]$.
- and . Hence, .
In the fourth test case, , and here is one possible sequence of operations.
- and . Hence, .
Samples
4
1 3
3
4 9
7 11 2 5
6 9
1 9 14 12 10 8
10 10
10 10 10 10 10 10 10 10 10 10
YES
NO
YES
YES
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