input: Write a function to convert a positive integer to negative or vice versa using the bitwise NOT operator. Provide two functions: one to convert a positive integer to negative and another to convert a negative integer to positive. The functions should utilize the bitwise NOT operator to achieve the conversion.
  
  def convert_to_negative(x):
      return ~x + 1
  
  def convert_to_positive(x):
      return ~(x - 1)
  
  assert convert_to_negative(10) == -10
  assert convert_to_negative(25) == -25
  assert convert_to_positive(-10) == 10
  assert convert_to_positive(-25) == 25
  assert convert_to_negative(0) == 0
  assert convert_to_positive(0) == 0
output: def convert_to_negative(x):
      return ~x + 1
  
  def convert_to_positive(x):
      return ~(x - 1)