hackerrank Type of Triangle
1) 정사각형 A=B AND B=C
1-1)
SELECT
CASE
WHEN A=B AND B=C THEN 'Equilateral'
ELSE '그외'
END, A, B, C
FROM TRIANGLES
2) 이등변 삼각형
2-1)
SELECT
CASE
WHEN A=B AND B=C THEN 'Equilateral'
WHEN A=B OR A=C OR B=C THEN 'Isosceles'
ELSE '그외'
END, A, B, C
FROM TRIANGLES
2-2)
SELECT
CASE
WHEN A=B AND B=C THEN 'Equilateral'
WHEN A=B AND A+B>C
OR A=C AND A+C>B
OR B=C AND B+C>A THEN 'Isosceles'
ELSE '그외'
END, A, B, C
FROM TRIANGLES
3) 삼각형이 아닌 형태
3-1)
SELECT
CASE
WHEN A=B AND B=C THEN 'Equilateral'
WHEN A=B AND A+B>C
OR A=C AND A+C>B
OR B=C AND B+C>A THEN 'Isosceles'
WHEN A+B<=C OR A+C<=B OR B+C<=A THEN 'Not A Triangle'
ELSE '그외'
END, A, B, C
FROM TRIANGLES
3-2)
SELECT
CASE
WHEN A=B AND B=C THEN 'Equilateral'
WHEN A=B AND A+B>C
OR A=C AND A+C>B
OR B=C AND B+C>A THEN 'Isosceles'
WHEN A+B<=C OR A+C<=B OR B+C<=A THEN 'Not A Triangle'
ELSE 'Scalene'
END
FROM TRIANGLES
SUCCESS!