- Practice
- Algorithms
- Dynamic Programming
- Grid Walking

# Grid Walking

# Grid Walking

You are situated in an dimensional grid at position . The dimensions of the grid are . In one step, you can walk one step ahead or behind in any one of the dimensions. This implies that there are always possible moves if movements are unconstrained by grid boundaries. How many ways can you take steps without leaving the grid at any point? You leave the grid if at any point , either or .

For example, you start off in a 3 dimensional grid at position . The dimensions of the grid are , so each of your axes will be numbered from to . If you want to move step, you can move to the following coordinates: .

If we started at in the same grid, our new paths would lead to . Other moves are constrained by .

**Function Description**

Complete the *gridWalking* function in the editor below. It should return an integer that represents the number of possible moves, modulo .

gridWalking has the following parameter(s):

*m*: an integer that represents the number of steps*x*: an integer array where each represents a coordinate in the dimension where*D*: an integer array where each represents the upper limit of the axis in the dimension

**Input Format**

The first line contains an integer , the number of test cases.

Each of the next sets of lines is as follows:

- The first line contains two space-separated integers, and .
- The next line contains space-separated integers .
- The third line of each test contains space-separated integers .

**Constraints**

**Output Format**

Output one line for each test case. Since the answer can be really huge, output it modulo .

**Sample Input**

```
1
2 3
1 1
2 3
```

**Sample Output**

```
12
```

**Explanation**

We are starting from (1, 1) in a 2-D grid, and need to count the number of possible paths with length equal to .

Here are the paths: