Puzzleup 2012 (6) Three Pawns in a Frame - 西洋棋

題目網址: http://www.puzzleup.com/2012/?home
http://www.puzzleup.com/2012/puzzle/?247
答題時限: ８月30日７ＰＭ－比賽結束（約１２月１２日）
加分時限: ８月30日７ＰＭ－９月４日６：５９ＰＭ

答對可得基本分１００分。答案可上傳５次，每改１次答案從基本分扣２０分。
另有兩種加分： １. 加分時限內答對。例：第Ｎ天答對，可加（６－Ｎ）分。
２. 題目越困難，加分越多。例：這題有ｎ％的人答錯，答對者加ｎ分。

◆Three Pawns in a Frame

There is a square wire frame with a side length of X units (integer), a
chessboard with a side length of 8 units, and 33 pawns to be placed randomly
on this board.

What is the minimum value for X, if it is possible to place the frame on the
board to cover at least 3 pawns, for every possible placement of the 33 pawns
on the board.

Note: For the frame to cover a pawn, it needs to fully cover the square the
pawn is on.

有一個正方形框架，邊長為 X 單位(X 為整數)，一個邊長為八單位的西洋棋盤，
以及隨機在這盤子上放置的 33 個小兵。

求 X 的最小值，使得無論這 33 個小兵在盤上怎麼擺，
都能夠將這框架放在棋盤上，使得它框住至少三個小兵。

注意：要使這個框架框住某個小兵，它必須完全包含該小兵所在的方格。

--
雖然沒有明說，但這樣子的敘述方式我覺得應該這正方框只能貼格線放...

(也就是說沒有那種搞怪的斜放法就是了)

這樣一來這題似乎沒什麼好玩的 (思)

9/5 edit:

新題快出了才看到原題補了個跟我的猜測差不多的 Note...

我也補上去好了 (思

--
'You've sort of made up for it tonight,' said Harry. 'Getting the
sword. Finishing the Horcrux. Saving my life.'
'That makes me sound a lot cooler then I was,' Ron mumbled.
'Stuff like that always sounds cooler then it really was,' said
Harry. 'I've been trying to tell you that for years.'
-- Harry Potter and the Deathly Hollows, P.308

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