title: Traversing a complete binary min heap
body: <p>I am not sure how to traverse the tree structure below so that the nodes are always in ascending order. Heapifying the array <code>[9 8 7 6 5 4 3 2 1 0]</code> results in the array <code>[0 1 3 2 5 4 7 9 6 8]</code> which I think corresponds to this representation:</p>
  
  <p><img src="https://i.stack.imgur.com/nSrur.png" alt="heap drawing"></p>
  
  <p>Wanting to keep the array as is (because I want to do efficient inserts later) how can I efficiently traverse it in ascending order? (That is visiting the nodes in this order <code>[0 1 2 3 4 5 6 7 8 9]</code>)</p>