title: computational complexity exercise
body: <p>I'm reading "Data structures and algorithms" from Aho, Hopcroft &amp; Ullman, and I'm confused with exercise 1.12 B:</p>
  
  <p>Which is the computational complexity (expressed in Big O notation) of this Pascal procedure?</p>
  
  <pre><code>procedure mysterious( n: integer );
      var
          i, j, k: integer;
      begin
          for i := 1 to n - 1 do
               for j := i + 1 to n do
                   for k := 1 to j do
                      {mysterious statement of O(1)}
      end
  </code></pre>
  
  <p>Could you please help me?</p>
  
  <p>Thanks!</p>