input: Write a function to convert a number into binary format. The function should return the binary representation of the given number as a string. If the given 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
  
  # Test cases
  assert convert_to_binary(10) == '1010'
  assert convert_to_binary(0) == '0'
  assert convert_to_binary(1) == '1'
  assert convert_to_binary(255) == '11111111'
  assert convert_to_binary(64) == '1000000'
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