2015年7月23日

摘要： Description A math instructor is too lazy to grade a question in the exam papers in which students are supposed to produce a complicated formula for t 阅读全文

摘要： Description 在N*N的方格棋盘放置了N个皇后，使得它们不相互攻击（即任意2个皇后不允许处在同一排，同一列，也不允许处在与棋盘边框成45角的斜线上。 你的任务是，对于给定的N，求出有多少种合法的放置方法。 Description 在N*N的方格棋盘放置了N个皇后，使得它们不相互攻击（即任意 阅读全文

摘要： Description Due to recent rains, water has pooled in various places in Farmer John's field, which is represented by a rectangle of N x M (1 <= N <= 10 阅读全文