### Find the Width of Columns of a Grid

You are given a **0-indexed** `m x n` integer matrix `grid`. The width of a column is the maximum **length** of its integers.

- For example, if `grid = [[-10], [3], [12]]`, the width of the only column is `3` since `-10` is of length `3`.

Return *an integer array* `ans` *of size* `n` *where* `ans[i]` *is the width of the* `ith` *column*.

The **length** of an integer `x` with `len` digits is equal to `len` if `x` is non-negative, and `len + 1` otherwise.

 

**Example 1:**

```
Input: grid = [[1],[22],[333]]
Output: [3]
Explanation: In the 0th column, 333 is of length 3.
```

**Example 2:**

```
Input: grid = [[-15,1,3],[15,7,12],[5,6,-2]]
Output: [3,1,2]
Explanation: 
In the 0th column, only -15 is of length 3.
In the 1st column, all integers are of length 1. 
In the 2nd column, both 12 and -2 are of length 2.
```

 

**Constraints:**

- `m == grid.length`
- `n == grid[i].length`
- `1 <= m, n <= 100 `
- `-10^9 <= grid[r][c] <= 10^9`

**Function definition**

```
class Solution:
    def findColumnWidth(self, grid: List[List[int]]) -> List[int]:
```