input: Write a function to convert a number into its binary format. The function should take an integer as input and return its binary representation as a string. If the input number is 0, the function should return 0.
  def convert_to_binary(num):
      if num == 0:
          return "0"
      
      binary = ''
      
      while num != 0:
          remainder = num % 2
          binary = str(remainder) + binary
          num = num // 2
      
      return binary
  
  assert convert_to_binary(0) == "0"
  assert convert_to_binary(10) == "1010"
  assert convert_to_binary(7) == "111"
  assert convert_to_binary(16) == "10000"
  assert convert_to_binary(3) == "11"
output: def convert_to_binary(num):
      if num == 0:
          return "0"
      
      binary = ''
      
      while num != 0:
          remainder = num % 2
          binary = str(remainder) + binary
          num = num // 2
      
      return binary