title: Vector intersection in C++
body: <p>I have this function</p>
  
  <pre><code>vector&lt;string&gt; instersection(const vector&lt;string&gt; &amp;v1, const vector&lt;string&gt; &amp;v2);
  </code></pre>
  
  <p>I have two vectors of strings and I want to find the strings that are present in both, which then fills a third vector with the common elemnts. </p>
  
  <p>If my vectors are...</p>
  
  <pre><code>v1 = &lt;"a","b","c"&gt;
  v2 = &lt;"b","c"&gt;
  </code></pre>