Weather Observation Station 20 (HackerRank)

Weather Observation Station 20 | HackerRank

A median is defined as a number separating the higher half of a data set from the lower half. Query the median of the Northern Latitudes (LAT_N) from STATION and round your answer to  decimal places.

풀이

제출한 답

with sub as (
select *, row_number() over (order by lat_n) rw, count(*) over () cnt
from station)

select round(avg(lat_n),4)
from sub
where case when mod(cnt,2) = 1 then rw = (cnt+1)/2
else rw in (cnt/2, (cnt/2)+1) end

-> 갯수는 cnt, 행 번호는 rw, 갯수가 짝수일 때는 두 값을 평균내야 함

2022.11.07