Advent Of Code - Day 4

HTML

<script src="//crypto-js.googlecode.com/svn/tags/3.1.2/build/rollups/md5.js"></script>
<input type="text" placeholder="secret key" />
<p></p>

JavaScript

$('input').change(function() {

  var seckey = $('input').val();
  var hashFound = false;
  var n = 0;
  var startingZeroes = 6;

  while (!hashFound) {
    n++;
    var hash = CryptoJS.MD5(seckey + n).toString();
    var start = hash.substring(0, startingZeroes);

    if (start == '0'.repeat(startingZeroes)) {
      hashFound = true;
      $('p').text('Lowest Possible Number For ' + startingZeroes + ' Zeroes : ' + n);
    }

  }

});