<p>Given a <code>date</code> string in the form <code>Day Month Year</code>, where:</p>
<ul>
<li><code>Day</code> is in the set <code>{"1st", "2nd", "3rd", "4th", ..., "30th", "31st"}</code>.</li>
<li><code>Month</code> is in the set <code>{"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}</code>.</li>
<li><code>Year</code> is in the range <code>[1900, 2100]</code>.</li>
</ul>
<p>Convert the date string to the format <code>YYYY-MM-DD</code>, where:</p>
<ul>
<li><code>YYYY</code> denotes the 4 digit year.</li>
<li><code>MM</code> denotes the 2 digit month.</li>