title: Algorithms in O(n^2) vs O(n)
body: <p>I'm new to computer science and just started with pseudocodes and I have some questions. It's my third week in the semester and majority is self-studying. I have some questions:</p>
  
  <p>What is the difference of an O(n^2) with an O(n) algorithm? 
  - Similarly, what is O(n log n)?
  - and Ω(n^2)?</p>
  
  <p>So far, I have written:</p>
  
  <pre><code>horner = 0;
  for( i = n; i &gt;= 0; i −− )
      horner = x * horner + a[i];
  </code></pre>
  
  <p>But found out it is O(n). How do I transform it?</p>
  
  <p>What is the run time?
  - I know assignment on first line is 1 operation</p>
  
  <p>And how does it look like in an actual, say C#, algorithm?</p>