A13376. Two Arrays And Swaps

You are given two arrays $a$ and $b$ both consisting of $n$ positive (greater than zero) integers. You are also given an integer $k$ .

In one move, you can choose two indices $i$ and $j$ ( $1 \le i, j \le n$ ) and swap $a_i$ and $b_j$ (i.e. $a_i$ becomes $b_j$ and vice versa). Note that $i$ and $j$ can be equal or different (in particular, swap $a_2$ with $b_2$ or swap $a_3$ and $b_9$ both are acceptable moves).

Your task is to find the maximum possible sum you can obtain in the array $a$ if you can do no more than (i.e. at most) $k$ such moves (swaps).

You have to answer $t$ independent test cases.

The first line of the input contains one integer $t$ ( $1 \le t \le 200$ ) — the number of test cases. Then $t$ test cases follow.

The first line of the test case contains two integers $n$ and $k$ ( $1 \le n \le 30; 0 \le k \le n$ ) — the number of elements in $a$ and $b$ and the maximum number of moves you can do. The second line of the test case contains $n$ integers $a_1, a_2, \dots, a_n$ ( $1 \le a_i \le 30$ ), where $a_i$ is the $i$ -th element of $a$ . The third line of the test case contains $n$ integers $b_1, b_2, \dots, b_n$ ( $1 \le b_i \le 30$ ), where $b_i$ is the $i$ -th element of $b$ .

For each test case, print the answer — the maximum possible sum you can obtain in the array $a$ if you can do no more than (i.e. at most) $k$ swaps.

In the first test case of the example, you can swap $a_1 = 1$ and $b_2 = 4$ , so $a=[4, 2]$ and $b=[3, 1]$ .

In the second test case of the example, you don't need to swap anything.

In the third test case of the example, you can swap $a_1 = 1$ and $b_1 = 10$ , $a_3 = 3$ and $b_3 = 10$ and $a_2 = 2$ and $b_4 = 10$ , so $a=[10, 10, 10, 4, 5]$ and $b=[1, 9, 3, 2, 9]$ .

In the fourth test case of the example, you cannot swap anything.

In the fifth test case of the example, you can swap arrays $a$ and $b$ , so $a=[4, 4, 5, 4]$ and $b=[1, 2, 2, 1]$ .