【leetcode】610. Triangle Judgement

原题

A pupil Tim gets homework to identify whether three line segments could possibly form a triangle.
However, this assignment is very heavy because there are hundreds of records to calculate.
Could you help Tim by writing a query to judge whether these three sides can form a triangle, assuming table triangle holds the length of the three sides x, y and z.

x	y	z
13	15	30
10	20	15

For the sample data above, your query should return the follow result:

x	y	z	triangle
13	15	30	No
10	20	15	Yes

解析

给一组xyz，代表三角形的三边
写sql输出，判断三边是否能组成三角形

思路

我的思路本是想判断三边中最长的边是不是大于其余两边之和，但是太麻烦，可以直接三边都判断

解法

SELECT 
    x,
    y,
    z,
    CASE
        WHEN x + y > z AND x + z > y AND y + z > x THEN 'Yes'
        ELSE 'No'
    END AS 'triangle'
FROM
    triangle
;