title: How can one determine vector size at run time?
body: <p>At run time, can one determine the size of a <code>vector</code>?</p>
  
  <p>For example</p>
  
  <p>input :  25  // which shows vector size</p>
  
  <pre><code>  code :
          int N ;
          cin &lt;&lt; N ;
          vector &lt;int&gt; data[N];
  </code></pre>