<p>Winter is coming! During the contest, your first job is to design a standard heater with a fixed warm radius to warm all the houses.</p>
<p>Every house can be warmed, as long as the house is within the heater's warm radius range. </p>
<p>Given the positions of <code>houses</code> and <code>heaters</code> on a horizontal line, return <em>the minimum radius standard of heaters so that those heaters could cover all houses.</em></p>
<p><strong>Notice</strong> that all the <code>heaters</code> follow your radius standard, and the warm radius will the same.</p>