https://www.hackerrank.com/challenges/full-score/problem Top Competitors | HackerRank Query a list of top-scoring hackers. www.hackerrank.com select h.hacker_id, h.name from submissions s left join hackers h on s.hacker_id = h.hacker_id left join challenges c on c.challenge_id = s.challenge_id left join difficulty d on d.difficulty_level = c.difficulty_level where s.score = d.score and d.difficu..