title: Find which numbers appears most in a vector
body: <p>I have some numbers stored in a <code>std::vector&lt;int&gt;</code>. I want to find which number appears most in the vector.</p>
  <p>e.g. in the vector</p>
  <pre><code>1 3 4 3 4 2 1 3 2 3
  </code></pre>
  <p>the element that occurs the most is <code>3</code>.</p>
  <p>Is there any algorithm (STL or whatever) that does this ?</p>