308547: CF1537A. Arithmetic Array
Memory Limit:256 MB
Time Limit:1 S
Judge Style:Text Compare
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Description
Arithmetic Array
题意翻译
若长度为 $k$ 的序列 $b$ 的平均值为 $1$,我们认为这个序列是好的。 现在给你一个长度为 $n$ 的序列 $a$。每次操作时,你可以将一个非负整数追加到序列末尾。 若要使原序列变好,求最小操作次数。 可以证明存在有限步数使序列变好。题目描述
An array $ b $ of length $ k $ is called good if its arithmetic mean is equal to $ 1 $ . More formally, if $ $\frac{b_1 + \cdots + b_k}{k}=1. $ $ </p><p>Note that the value $ \\frac{b\_1+\\cdots+b\_k}{k} $ is not rounded up or down. For example, the array $ \[1,1,1,2\] $ has an arithmetic mean of $ 1.25 $ , which is not equal to $ 1 $ .</p><p>You are given an integer array $ a $ of length $ n$. In an operation, you can append a non-negative integer to the end of the array. What's the minimum number of operations required to make the array good? We have a proof that it is always possible with finitely many operations.输入输出格式
输入格式
The first line contains a single integer $ t $ ( $ 1 \leq t \leq 1000 $ ) — the number of test cases. Then $ t $ test cases follow. The first line of each test case contains a single integer $ n $ ( $ 1 \leq n \leq 50 $ ) — the length of the initial array $ a $ . The second line of each test case contains $ n $ integers $ a_1,\ldots,a_n $ ( $ -10^4\leq a_i \leq 10^4 $ ), the elements of the array.
输出格式
For each test case, output a single integer — the minimum number of non-negative integers you have to append to the array so that the arithmetic mean of the array will be exactly $ 1 $ .
输入输出样例
输入样例 #1
4
3
1 1 1
2
1 2
4
8 4 6 2
1
-2
输出样例 #1
0
1
16
1