摘要：
题目链接： http://acm.hdu.edu.cn/showproblem.php?pid=5882 Problem Description Rock-paper-scissors is a zero-sum hand game usually played between two people 阅读全文
摘要：
题目链接： http://acm.hdu.edu.cn/showproblem.php?pid=5879 Problem Description Given an integer n , we only want to know the sum of 1/k2 where k from 1 to n 阅读全文