摘要: 题目链接:http://poj.org/problem?id=2917 题目大意:给定n,求有多少种1/x + 1/y = 1/n成立(x,y为正整数)思路:一道很经典的数论题.我们不妨设x>=y,则x=n+1,n+2,……,n+n.而y = 1 / (1/n - 1/x) = nx / (x - ... 阅读全文
posted @ 2012-12-28 23:59 AbandonZHANG 阅读(152) 评论(0) 推荐(0)
摘要: 题目链接:http://poj.org/problem?id=2917 题目大意:给定n,求有多少种1/x + 1/y = 1/n成立(x,y为正整数)思路:一道很经典的数论题.我们不妨设x>=y,则x=n+1,n+2,……,n+n.而y = 1 / (1/n - 1/x) = nx / (x - ... 阅读全文
posted @ 2012-12-28 23:59 AbandonZHANG 阅读(166) 评论(0) 推荐(0)