title: c - optimizing repetitive if else
body: <p>I have the following code:</p>
  
  <pre><code>if (a1 &lt; a2)
     a3=0;
  else
     a3=a1-a2;
  
  if (b1 &lt; b2)
     b3=0;
  else
     b3=b1-b2;
  
  if (c1 &lt; c2)
     c3=0;
  else
     c3=c1-c2;
  </code></pre>
  
  <p>The code is quite repetitive. Any suggestions on optimize code size? I do not want to use array.</p>