title: Simplifying O(nm) and O(n + m) time complexity
body: <p>If I have a function that runs in <code>O(nm)</code> time complexity, is it common practice/acceptable to simplify that into just saying it runs in <code>O(n^2)</code> time complexity?  For example, a function like this:</p>
  
  <pre><code>function funcOne(nArray, mArray) {
      for (var i = 0; i &lt; nArray.length; i++) {
          for (var j = 0; j &lt; mArray.length; j++) {
  
              ....
  
          }
      }
  }
  </code></pre>
  
  <p>Also, if I have a function that runs in <code>O(n + m)</code> time complexity, is it common practice/acceptable to simplify that into just saying it runs in <code>O(n)</code> time complexity?  For example, a function like this: </p>
  
  <pre><code>function funcOne(nArray, mArray) {
      for (var i = 0; i &lt; nArray.length; i++) {
  
          ...
  
      }
  
      for (var j = 0; j &lt; mArray.length; j++) {
  
          ...
  
      }
  }
  </code></pre>