title: How allocate or free only parts of an array?
body: <p>See this example:</p>
  
  <pre><code>int *array = malloc (10 * sizeof(int))
  </code></pre>
  
  <p>Is there a way to free only the first 3 blocks?</p>
  
  <p>Or to have an array with negative indexes, or indexes that don't begin with 0?</p>