Problem

I was solving this question on a site that gives you a 1d array called `grid`

```
grid = ['top left', 'top middle', 'top right',
'middle left', 'center', 'middle right',
'bottom left', 'bottom middle', 'bottom right']
```

and you’re expected to write a method `fire(x,y)`

that takes in two coordinates and gives you back where you hit the grid.

For example:

```
fire(0,0) # 'top left'
fire(1,2) # 'bottom middle'
```

Here is my solution, I used NumPy for it.

```
import numpy as np
def fire(x,y):
#the grid is preloaded as you can see in description
oneDArray = np.array(grid)
twoDArray = oneDArray.reshape(3,3)
return twoDArray[y][x]
```

I’m looking to get some feedback on the answer.

Solution

That works, but if your only goal is to implement `fire(x, y)`

, then NumPy is overkill.

```
def fire(x, y):
return grid[3 * y + x]
```

A few issues:

- Probably better to follow pep8
- This isn’t a method, it is a function
- When doing 2D
`numpy`

indexes, you can do`twoDArray[x, y]`

- You don’t really need a numpy array, a list of lists works just as well. Or better yet just just translate the 2D index into a linear index mathematically. This also avoids the substantial overhead of converting the list to a numpy array. You could even use
`np.ravel_multi_index`

to do the 2D to 1D conversion for you.