title: Difference between graphs and asymptotic analysis to compare running times of an algorithm
body: <p>The question pretty much states what i'm asking for.</p>
  
  <p>I have an algorithm and I was wandering what is the better approach to achieve ah 'Big-Oh' running time - through a graph and plotting the number of input against the running time, or through asymptotic analysis?</p>
  
  <p>For my graph I'm currently using:</p>
  
  <pre><code>private int startTime = System.currentTimeMillis(); //At start of algorithm
  private int endTime = System.currentTimeMillis(); //At the end of algorithm
  int runningTime = endTime - startTime;
  </code></pre>
  
  <p>What's the difference between both methods of 'measuring' the running time of an alogrithm?</p>