input: Write a function to convert a positive integer to a negative integer and vice versa using the bitwise NOT operator. Provide the function to covert positive to negative and the function to convert negative to positive both in a single return.
  assert convert_to_negative(5)==-5
  assert convert_to_negative(-3)==3
  assert convert_to_positive(-5)==5
  assert convert_to_positive(3)==-3
  assert convert_to_negative(0)==0
  assert convert_to_positive(0)==0
output: def convert_to_negative(n):
      return ~n + 1
  
  def convert_to_positive(n):
      return ~n + 1