Codeforces Round 803 (Div. 2) |
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Finished |
You are given a permutation $$$a$$$ of length $$$n$$$. Recall that permutation is an array consisting of $$$n$$$ distinct integers from $$$1$$$ to $$$n$$$ in arbitrary order.
You have a strength of $$$s$$$ and perform $$$n$$$ moves on the permutation $$$a$$$. The $$$i$$$-th move consists of the following:
You want to turn $$$a$$$ into another permutation $$$b$$$ after $$$n$$$ moves. However, some elements of $$$b$$$ are missing and are replaced with $$$-1$$$ instead. Count the number of ways to replace each $$$-1$$$ in $$$b$$$ with some integer from $$$1$$$ to $$$n$$$ so that $$$b$$$ is a permutation and it is possible to turn $$$a$$$ into $$$b$$$ with a strength of $$$s$$$.
Since the answer can be large, output it modulo $$$998\,244\,353$$$.
The input consists of multiple test cases. The first line contains an integer $$$t$$$ ($$$1 \leq t \leq 1000$$$) — the number of test cases. The description of the test cases follows.
The first line of each test case contains two integers $$$n$$$ and $$$s$$$ ($$$1 \leq n \leq 2 \cdot 10^5$$$; $$$1 \leq s \leq n$$$) — the size of the permutation and your strength, respectively.
The second line of each test case contains $$$n$$$ integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \le a_i \le n$$$) — the elements of $$$a$$$. All elements of $$$a$$$ are distinct.
The third line of each test case contains $$$n$$$ integers $$$b_1, b_2, \ldots, b_n$$$ ($$$1 \le b_i \le n$$$ or $$$b_i = -1$$$) — the elements of $$$b$$$. All elements of $$$b$$$ that are not equal to $$$-1$$$ are distinct.
It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
For each test case, output a single integer — the number of ways to fill up the permutation $$$b$$$ so that it is possible to turn $$$a$$$ into $$$b$$$ using a strength of $$$s$$$, modulo $$$998\,244\,353$$$.
63 12 1 33 -1 -13 22 1 33 -1 -14 11 4 3 24 3 1 26 44 2 6 3 1 56 1 5 -1 3 -17 41 3 6 2 7 4 52 5 -1 -1 -1 4 -114 141 2 3 4 5 6 7 8 9 10 11 12 13 14-1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
1 2 0 2 12 331032489
In the first test case, $$$a=[2,1,3]$$$. There are two possible ways to fill out the $$$-1$$$s in $$$b$$$ to make it a permutation: $$$[3,1,2]$$$ or $$$[3,2,1]$$$. We can make $$$a$$$ into $$$[3,1,2]$$$ with a strength of $$$1$$$ as follows: $$$$$$[2,1,3] \xrightarrow[x=1,\,y=1]{} [2,1,3] \xrightarrow[x=2,\,y=3]{} [3,1,2] \xrightarrow[x=3,\,y=3]{} [3,1,2].$$$$$$ It can be proven that it is impossible to make $$$[2,1,3]$$$ into $$$[3,2,1]$$$ with a strength of $$$1$$$. Thus only one permutation $$$b$$$ satisfies the constraints, so the answer is $$$1$$$.
In the second test case, $$$a$$$ and $$$b$$$ the same as the previous test case, but we now have a strength of $$$2$$$. We can make $$$a$$$ into $$$[3,2,1]$$$ with a strength of $$$2$$$ as follows: $$$$$$[2,1,3] \xrightarrow[x=1,\,y=3]{} [2,3,1] \xrightarrow[x=2,\,y=3]{} [3,2,1] \xrightarrow[x=3,\,y=3]{} [3,2,1].$$$$$$ We can still make $$$a$$$ into $$$[3,1,2]$$$ using a strength of $$$1$$$ as shown in the previous test case, so the answer is $$$2$$$.
In the third test case, there is only one permutation $$$b$$$. It can be shown that it is impossible to turn $$$a$$$ into $$$b$$$, so the answer is $$$0$$$.
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