我对 Bejewelled 游戏带来的编程挑战很感兴趣。它看起来像一个简单的游戏,但在编程上它看起来更复杂。
在寻找有关如何评估董事会的提示时,我遇到了 Simple-Talk 的好人提出的这个测验。他们已经发布了获胜的答案,但是如果我真的能理解解决方案的工作原理,我会感到很震惊。我可以看到它与矩阵有关,并将单元格值与其行和列分组在一起,但这是我到目前为止所获得的。任何人都可以为我进一步分解它吗?
发布的解决方案(测验的详细信息在上面的链接中):
--====== Table matches needs to be loaded only once
CREATE TABLE matches(offsetRow1 INT, offsetCol1 INT, offsetRow2 INT, ofsetCol2 INT, directions VARCHAR(20))
-- for horizontal
INSERT INTO matches VALUES(-1, -1, -1, -2, 'up')
INSERT INTO matches VALUES(-1, -1, -1, 1, 'up')
INSERT INTO matches VALUES(-1, 1, -1, 2, 'up')
INSERT INTO matches VALUES( 1, -1, 1, -2, 'down')
INSERT INTO matches VALUES( 1, -1, 1, 1, 'down')
INSERT INTO matches VALUES( 1, 1, 1, 2, 'down')
INSERT INTO matches VALUES( 0, -2, 0, -3, 'left')
INSERT INTO matches VALUES( 0, 2, 0, 3, 'right')
-- for verical
INSERT INTO matches VALUES(-2, -1, -1, -1, 'left')
INSERT INTO matches VALUES(-1, -1, 1, -1, 'left')
INSERT INTO matches VALUES( 1, -1, 2, -1, 'left')
INSERT INTO matches VALUES(-2, 1, -1, 1, 'right')
INSERT INTO matches VALUES(-1, 1, 1, 1, 'right')
INSERT INTO matches VALUES( 1, 1, 2, 1, 'right')
INSERT INTO matches VALUES(-2, 0, -3, 0, 'up')
INSERT INTO matches VALUES( 2, 0, 3, 0, 'down')
--==================================================
;WITH CTE
AS
(
SELECT
[Row] = CAST( [#] AS INT ),
[Col] = CAST( [Col] AS INT ),
[Value]
FROM bejeweled
UNPIVOT ([Value] FOR [Col] IN ([1],[2],[3],[4],[5],[6],[7],[8],[9])) unpvt
)
SELECT DISTINCT T.Row, T.Col, T.Value, directions
FROM CTE T
JOIN CTE T1
ON T.Value = T1.Value
JOIN CTE T2
ON T.Value = T2.Value
JOIN matches
ON (T1.Row - T.Row) = offsetRow1
AND (T1.Col - T.Col) = offsetCol1
AND (T2.Row - T.Row) = offsetRow2
AND (T2.Col - T.Col) = ofsetCol2
ORDER BY T.Row, T.Col