题目：原题链接（困难）

标签：SQL

解法 时间复杂度 空间复杂度 执行用时
Ans 1 (Python) 849ms (34.83%)
Ans 2 (Python)
Ans 3 (Python)

解法一：

SELECT period_state,
       MIN(T.date) AS start_date,
       MAX(T.date) AS end_date
FROM (SELECT success_date AS date,
             'succeeded' AS period_state,
             IF(DATEDIFF(@pre_date, @pre_date := success_date) = -1, @id, @id := @id + 1) AS id
      FROM Succeeded,
           (SELECT @id := 0, @pre_date := NULL) AS Param
      UNION
      SELECT fail_date AS date,
             'failed' AS period_state,
             IF(DATEDIFF(@pre_date, @pre_date := fail_date) = -1, @id, @id := @id + 1) AS id
      FROM Failed,
           (SELECT @id := 0, @pre_date := NULL) AS Param
     ) AS T
WHERE date BETWEEN '2019-01-01' AND '2019-12-31'
GROUP BY T.id
ORDER BY start_date;