title: How to convert integer to binary string in C#?
body: <p>I'm writing a number converter. How can I convert a integer to a binary string in C# WITHOUT using built-in functions (<code>Convert.ToString</code> does different things based on the value given)?</p>
  
  <ul>
  <li>Binary -> Sign magnitude</li>
  <li>Binary -> One's complement</li>
  <li>Binary > Two's complement</li>
  </ul>