title: Finding the key whose value is the lowest value in a hashmap
body: <p>I'm trying to come up with an efficient way to return a key in my <code>HashMap</code> that has the lowest value in datastructure. Is there a quick and efficient way to do this besides looping through the entire <code>HashMap</code>?</p>
  
  <p>For example, if I have a hashmap that looks like this:</p>
  
  <pre><code>1: 200
  3: 400
  5: 1
  </code></pre>
  
  <p>I want to return the key, 5.</p>