摘要:
Recently a dog was bought for Polycarp. The dog's name is Cormen. Now Polycarp has a lot of troubles. For example, Cormen likes going for a walk. Empi 阅读全文
摘要:
链接:https://ac.nowcoder.com/acm/contest/275/A 题目描述 你在一栋楼房下面,楼房一共有n层,第i层每秒有pi的概率会扔下一个东西并砸到你 求第一秒内你被砸到的概率 输入描述: 第一行一个整数n之后有n行,第i+1行有两个整数a i ,b i ,表示 输出描述 阅读全文