input: Write a function to generate a two-dimensional array filled with zeros. The function should take two parameters: row and col, representing the number of rows and columns respectively. If the input values are invalid (e.g., negative numbers), the function should return an empty list.
  assert generate_zeros_array(3,3)==[[0,0,0],[0,0,0],[0,0,0]]
  assert generate_zeros_array(2,4)==[[0,0,0,0],[0,0,0,0]]
  assert generate_zeros_array(0,3)==[]
  assert generate_zeros_array(1,0)==[]
  assert generate_zeros_array(-1,2)==[]
output: def generate_zeros_array(row, col):
      if row < 0 or col < 0:
          return []
      return [[0] * col for _ in range(row)]