题目网址: http://www.puzzleup.com/2012/?home http://www.puzzleup.com/2012/puzzle/?247 答题时限: ８月30日７ＰＭ－比赛结束（约１２月１２日） 加分时限: ８月30日７ＰＭ－９月４日６：５９ＰＭ 答对可得基本分１００分。答案可上传５次，每改１次答案从基本分扣２０分。 另有两种加分： １. 加分时限内答对。例：第Ｎ天答对，可加（６－Ｎ）分。 ２. 题目越困难，加分越多。例：这题有ｎ％的人答错，答对者加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. 有一个正方形框架，边长为 X 单位(X 为整数)，一个边长为八单位的西洋棋盘， 以及随机在这盘子上放置的 33 个小兵。 求 X 的最小值，使得无论这 33 个小兵在盘上怎麽摆， 都能够将这框架放在棋盘上，使得它框住至少三个小兵。 注意：要使这个框架框住某个小兵，它必须完全包含该小兵所在的方格。 -- 虽然没有明说，但这样子的叙述方式我觉得应该这正方框只能贴格线放... (也就是说没有那种搞怪的斜放法就是了) 这样一来这题似乎没什麽好玩的 (思) 9/5 edit: 新题快出了才看到原题补了个跟我的猜测差不多的 Note... 我也补上去好了 (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 --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 180.218.108.125 ※ 编辑: LPH66 来自: 180.218.108.125 (09/05 18:48)