HackerRank 공부 4

https://www.hackerrank.com/challenges/full-score/problem

Top Competitors | HackerRank

 

문제 핵심

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Write a query to print the respective hacker_id and name of hackers who achieved full scores for more than one challenge. Order your output in descending order by the total number of challenges in which the hacker earned a full score. If more than one hacker received full scores in same number of challenges, then sort them by ascending hacker_id.

 

다른 사람 풀이

select h.hacker_id, h.name
from hackers h
join submissions s on s.hacker_id = h.hacker_id
join challenges c on c.challenge_id = s.challenge_id
join difficulty d on (
    d.difficulty_level = c.difficulty_level and
    d.score = s.score
)
group by h.hacker_id, h.name
having count(*) > 1
order by count(*) desc, h.hacker_id asc

 

 

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https://www.hackerrank.com/challenges/placements/problem

Placements | HackerRank

 

내 풀이

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select t4.Name
from Friends t1
inner join Packages t2
on t1.ID = t2.ID
inner join Packages t3
on t1.Friend_ID = t3.ID
inner join Students t4
on t1.ID = t4.ID
WHERE t2.Salary < t3.Salary
order by t3.Salary
;