※ 引述《finaldark (......................)》之铭言： : 有没有人可以解释一下, : 我实在是看不懂, : 有人可以给个 hint吗 : 谢谢 : ********************************************************************* : 95年高考-程式设计 BNF: http://en.wikipedia.org/wiki/Backus%E2%80%93Naur_form : 二、试写出一BNF文法，使其产生二进位数字，且数字之值为3之倍数。（20分） : 答：3倍数之文法如下 : <N3> → <N3>0 | <N1>1 | 0 模三余零 = 余零的数 * 2 or 余一的数 * 2 + 1 or 0 : <N1> → <N2>0 | <N3>1 | 1 模三余一 = 模三余二 * 2 or 模三余零 * 2 + 1 or 1 : <N2> → <N1>0 | <N2>1 模三余二 = 模三余一 * 2 or 模三余二 * 2 + 1 : ********************************************************************* -- And in that line now was a whiskered old man, with a linen cap and a crooked nose, who waited in a place called the Stardust Band Shell to share his part of the secret of heaven: that each affects the other and the other affects the next, and the world is full of stories, but the stories are all one. --

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