I haven&#x27;t but I will check it out!<p>From my time at &#x2F;r&#x2F;cscareerquestions, LeetCode is the &quot;hardest&quot; and thus the best for top companies. HackerRank is good but every challenge requires parsing STDIN instead of just giving arguments to a function the user writes. It&#x27;s very annoying to me and a deal breaker, especially with certain languages.