input: Write a function to convert a positive integer to negative or vice versa using bitwise NOT operator. The function will have two parts: one for converting a positive integer to negative, and the other for converting a negative integer to positive. Each function takes an integer as input and returns the converted integer.
  
  assert convert_to_negative(5)==-5
  assert convert_to_negative(-8)==-8
  assert convert_to_positive(-3)==3
  assert convert_to_positive(10)==10
  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