#P7213. Cyber Painter
Cyber Painter
Problem Description
In the world of Cyberpunk, all paintings are done by using lasers. As a cyber painter, painting with lasers is your daily job.
You have a laser painting board with $n$ rows and $m$ columns of laser emitters. The distance between rows is $1$, and so is the distance between columns. Each laser emitter can emit a laser with a length of $0.5$ in four directions. Specifically, you can set an integer between $0$ and $15$ as the state value for each laser emitter, which can be denoted by a four-bit binary number $(X_1X_2X_3X_4)_2$ (For example, $11=(1011)_2$). The meaning of the state value is as follows:
- $X_1=1$: The laser emitter emits a laser of length $0.5$ in the upward direction.
- $X_2=1$: The laser emitter emits a laser of length $0.5$ in the right direction.
- $X_3=1$: The laser emitter emits a laser of length $0.5$ in the downward direction.
- $X_4=1$: The laser emitter emits a laser of length $0.5$ in the left direction.
Input
The first line contains an integer $T$ ($1 \le T \le 10^4$), indicating the number of test cases.
The first line of each test case contains two integers $n$ and $m$ ($1 \le n \times m \le 10^5$), indicating the number of rows and columns of the laser emitters.
The second line of each test case contains $16$ integers $a_0,a_1,\dots,a_{15}$ ($0\le a_i\le n\times m$, $\sum_{i=0}^{15}a_i=n \times m$), where $a_i$ indicates the number of integer $i$.
It guaranteed that the sum of $n\times m$ over all test cases won't exceed $10^6$.
Output
For each test case, output the expectation of the number of squares that can be formed by the laser in a single line. You should output the answer modulo $10^9+7$. Formally, let $M=10^9+7$. It can be shown that the answer can be expressed as an irreducible fraction $\frac{p}{q}$, where $p$ and $q$ are integers and $q\not\equiv 0\pmod M$. Output the integer equal to $p \times q^{-1}\bmod M$. In other words, output such an integer $x$ that $0 \le x < M$ and $x \cdot q \equiv p \pmod M$.
3
2 2
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4
2 2
0 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0
3 3
0 0 0 0 0 0 1 0 0 1 0 1 1 1 2 2
1
41666667
41699736
Hint
For the third test case in the sample, the following picture shows a possible assignment, which forms $3$ squares.
