title: how to get iterator to a particular position of a vector
body: <p>Suppose i have a </p>
  
  <pre><code>std::vector&lt;int&gt; v
  //and ...
  for(int i =0;i&lt;100;++i) 
   v.push_back(i);
  </code></pre>
  
  <p>now i want an iterator to, let's say 10th element of the vector.</p>
  
  <p>without doing the following approach</p>
  
  <pre><code>std::vector&lt;int&gt;::iterator vi;
  vi = v.begin();
  for(int i = 0;i&lt;10;i++)
    ++vi;
  </code></pre>
  
  <p>as this will spoil the advantage of having random access iterator for a vector.</p>