[SQL : HackerRank] Japan Population / Weather Observation Station 2 / Weather Observation Station 18

1] Japan Population

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>> 문제

Query the sum of the populations for all Japanese cities in CITY. The COUNTRYCODE for Japan is JPN.

Input Format

The CITY table is described as follows: 

 

>> 문제해결 코드

SELECT SUM(POPULATION)
from CITY 
WHERE COUNTRYCODE = 'JPN'

 

www.hackerrank.com/challenges/japan-population/problem

Japan Population | HackerRank

 

2] Weather Observation Station 2

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>> 문제

Query the following two values from the STATION table:

1. The sum of all values in LAT_N rounded to a scale of  2 decimal places.
2. The sum of all values in LONG_W rounded to a scale of  2 decimal places.

Input Format

The STATION table is described as follows:

 

where LAT_N is the northern latitude and LONG_W is the western longitude.

Output Format

Your results must be in the form:

lat lon

where  lat is the sum of all values in LAT_N and  lon is the sum of all values in LONG_W. Both results must be rounded to a scale of 2 decimal places.

 

 

>> 문제 해결 코드 

SELECT round(sum(lat_n), 2) AS lat , round(sum(long_w), 2) AS lon
FROM STATION

 

hackerrank.com/challenges/weather-observation-station-2/problem

Weather Observation Station 2 | HackerRank

 

3] Weather Observation Station 18

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>> 문제

Consider  P1(a,b ) and P2(c, d)  to be two points on a 2D plane.

•  a happens to equal the minimum value in Northern Latitude (LAT_N in STATION).
•  b happens to equal the minimum value in Western Longitude (LONG_W in STATION).
•  c happens to equal the maximum value in Northern Latitude (LAT_N in STATION).
•  d happens to equal the maximum value in Western Longitude (LONG_W in STATION).

Query the Manhattan Distance between points  p1 and p2  and round it to a scale of 4  decimal places.

: In a plane with p1 at (x1, y1) and p2 at (x2, y2), Manhattan Distance  is |x1 - x2| + |y1 - y2|.

 

Input Format

The STATION table is described as follows:

where LAT_N is the northern latitude and LONG_W is the western longitude.

 

>> 문제 해결 코드

select ROUND(ABS(min(LAT_N) - max(LAT_N)) + ABS(min(LONG_W) - Max(LONG_W)), 4)
from station

www.hackerrank.com/challenges/weather-observation-station-18/problem

Weather Observation Station 18 | HackerRank