P8128 [CF1998C] Perform Operations to Maximize Score
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题目描述

You are given an array $a$ of length $n$ and an integer $k$. You are also given a binary array $b$ of length $n$.

You can perform the following operation at most $k$ times:

  • Select an index $i$ ($1 \leq i \leq n$) such that $b_i = 1$. Set $a_i = a_i + 1$ (i.e., increase $a_i$ by $1$).

Your score is defined to be $\max\limits_{i = 1}^{n} \left( a_i + \operatorname{median}(c_i) \right)$, where $c_i$ denotes the array of length $n-1$ that you get by deleting $a_i$ from $a$. In other words, your score is the maximum value of $a_i + \operatorname{median}(c_i)$ over all $i$ from $1$ to $n$.

Find the maximum score that you can achieve if you perform the operations optimally.

For an arbitrary array $p$, $\operatorname{median}(p)$ is defined as the $\left\lfloor \frac{|p|+1}{2} \right\rfloor$-th smallest element of $p$. For example, $\operatorname{median} \left( [3,2,1,3] \right) = 2$ and $\operatorname{median} \left( [6,2,4,5,1] \right) = 4$.

Input

The first line contains an integer $t$ ($1 \leq t \leq 10^4$) — the number of test cases.

Each test case begins with two integers $n$ and $k$ ($2 \leq n \leq 2 \cdot 10^5$, $0 \leq k \leq 10^9$) — the length of the $a$ and the number of operations you can perform.

The following line contains $n$ space separated integers $a_1, a_2, \ldots, a_n$ ($1 \leq a_i \leq 10^9$) — denoting the array $a$.

The following line contains $n$ space separated integers $b_1, b_2, \ldots, b_n$ ($b_i$ is $0$ or $1$) — denoting the array $b$.

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output

For each test case, output the maximum value of score you can get on a new line.

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
8 2 10 3 3 1 1 3 10 3 3 3 0 0 0 4 4 2 1 5 1 0 1 0 1 5 4 7 5 2 5 4 0 0 1 0 1 5 1 5 15 15 2 11 1 0 0 1 1 5 2 10 11 4 10 15 1 1 0 1 0 4 4 1 1 2 5 1 1 0 0 2 1000000000 1000000000 1000000000 1 1
样例输出
16 6 8 13 21 26 8 3000000000
提示

For the first test case, it is optimal to perform $5$ operations on both elements so $a = [8,8]$. So, the maximum score we can achieve is $\max(8 + \operatorname{median}[8], 8 + \operatorname{median}[8]) = 16$, as $c_1 = [a_2] = [8]$. It can be proven that you cannot get a better score.

For the second test case, you are not able to perform operations on any elements, so $a$ remains $[3,3,3]$. So, the maximum score we can achieve is $3 + \operatorname{median}[3, 3] = 6$, as $c_1 = [a_2, a_3] = [3, 3]$. It can be proven that you cannot get a better score.