Matrix Padder

Create a function that takes a matrix of size (m, n) and returns a matrix of size (m+2, n+2) with a pad of 0s around the perimeter.

Examples

pad_matrix([[]]) ➞ [[0, 0], [0, 0], [0, 0]]

pad_matrix([[9]]) ➞ [
  [0, 0, 0],
  [0, 9, 0],
  [0, 0, 0]
]

pad_matrix([["hi", True]]) ➞ [
  [0, 0, 0, 0],
  [0, "hi", True, 0],
  [0, 0, 0, 0]
]

pad_matrix([
  [1, 2, 5],
  [8, 6, 7],
  [3, 4, 9]
]) ➞ [
  [0, 0, 0, 0, 0],
  [0, 1, 2, 5, 0],
  [0, 8, 6, 7, 0],
  [0, 3, 4, 9, 0],
  [0, 0, 0, 0, 0]
]

Notes

• All inputs will be lists of lists.
• Refer to the first example to handle an empty input.