F - 概率(经典问题) Time Limit:2000MS     Memory Limit:32768KB     64bit IO Format:%lld & %llu   Description Sometimes some mathematical results are hard to believe. One of the common problems is the birthday paradox. Suppose you are in a party where there…

E - 期望(经典问题) Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%lld & %llu   Description Given a dice with n sides, you have to find the expected number of times you have to throw that dice to see all its faces at least once. Assume that…

Sometimes some mathematical results are hard to believe. One of the common problems is the birthday paradox. Suppose you are in a party where there are 23 people including you. What is the probability that at least two people in the party have same b…

第六周H题 - 数论,晒素数 Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u   Description 小明对数的研究比较热爱,一谈到数,脑子里就涌现出好多数的问题,今天,小明想考考你对素数的认识.  问题是这样的:一个十进制数,如果是素数,而且它的各位数字和也是素数,则称之为“美素数”,如29,本身是素数,而且2+9 = 11也是素数,所以它是美素数.  给定一个区间,你能计算出这个区间…

第六周编程题 依照学术诚信条款,我保证此作业是本人独立完成的. 1 单词长度(4分) 题目内容: 你的程序要读入一行文本,其中以空格分隔为若干个单词,以'.'结束.你要输出这行文本中每个单词的长度.这里的单词与语言无关,可以包括各种符号,比如"it's"算一个单词,长度为4.注意,行中可能出现连续的空格. 输入格式: 输入在一行中给出一行文本,以'.'结束,结尾的句号不能计算在最后一个单词的长度内. 输出格式: 在一行中输出这行文本对应的单词的长度,每个长度之间以空格隔开,行末没有最后…

Description Gerald got a very curious hexagon for his birthday. The boy found out that all the angles of the hexagon are equal to . Then he measured the length of its sides, and found that each of them is equal to an integer number of centimeters. Th…

Description 大家常常感慨,要做好一件事情真的不容易,确实,失败比成功容易多了!  做好“一件”事情尚且不易,若想永远成功而总从不失败,那更是难上加难了,就像花钱总是比挣钱容易的道理一样.  话虽这样说,我还是要告诉大家,要想失败到一定程度也是不容易的.比如,我高中的时候,就有一个神奇的女生,在英语考试的时候,竟然把40个单项选择题全部做错了!大家都学过概率论,应该知道出现这种情况的概率,所以至今我都觉得这是一件神奇的事情.如果套用一句经典的评语,我们可以这样总结:一个人做错一道选择题…

ime Limit:2000MS     Memory Limit:32768KB     64bit IO Format:%lld & %llu   Description Sometimes some mathematical results are hard to believe. One of the common problems is the birthday paradox. Suppose you are in a party where there are 23 people…

Subsequence TimeLimit:1000MS  MemoryLimit:65536K 64-bit integer IO format:%lld   问题描述: A sequence of N positive integers (10 < N < 100 000), each of them less than or equal 10000, and a positive integer S (S < 100 000 000) are given. Write a prog…

t个数据 n天一年  至少2个人在同一天生日的概率>=0.5 问至少多少人 显然要从反面考虑 设365天 都在不同一天的概率 p(num)=1*364/365*363/365...; =(day***(day-num+1) )/(day)的num次: !p(num)=1-p(num); 而p(n)前一项和后一项更容易找规律 具体见代码 #include<stdio.h> int main() { int t,ca; scanf("%d",&t); ca=; w…