balls Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://acm.hdu.edu.cn/showproblem.php?pid=5570 Description There are n balls with m colors. The possibility of that the color of the i-th ball is color j is ai,jai,1+ai,2+...+ai,m. If the number of b…

Problem Description There are n balls with m colors. The possibility of that the color of the i-th ball +ai,+...+ai,m. If the number of balls with the j-th is x, then you should pay x2 as the cost. Please calculate the expectation of the cost. Input…

Balls Rearrangement 题目连接: http://acm.hdu.edu.cn/showproblem.php?pid=4611 Description Bob has N balls and A boxes. He numbers the balls from 0 to N-1, and numbers the boxes from 0 to A-1. To find the balls easily, he puts the ball numbered x into the…

意甲冠军:那是,  从数0-n小球进入相应的i%a箱号.然后买一个新的盒子. 今天的总合伙人b一个盒子,Bob试图把球i%b箱号. 求复位的最小成本. 每次移动的花费为y - x ,即移动前后盒子编号的差值的绝对值. 算法: 题目就是要求                  watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvdTAxMjg0MTg0NQ==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissol…

 Balls and Boxes(盒子与球) Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Description 题目描述 Mr. Chopsticks is interested in random phenomena, and he conducts an experiment to study randomness. In the experiment, he thr…

balls  Accepts: 19  Submissions: 55  Time Limit: 6000/3000 MS (Java/Others)  Memory Limit: 65536/65536 K (Java/Others) 问题描述 有nn个球,共有mm种颜色,第ii个球的颜色为jj的概率为\frac{a_{i,j}}{a_{i,1}+a_{i,2}+...+a_{i,m}}​a​i,1​​+a​i,2​​+...+a​i,m​​​​a​i,j​​​​. 对于第ii种颜色,若有xx…

Balls and Boxes 题目连接: http://acm.hdu.edu.cn/showproblem.php?pid=5810 Description Mr. Chopsticks is interested in random phenomena, and he conducts an experiment to study randomness. In the experiment, he throws n balls into m boxes in such a manner t…

Problem Description   You live in a village but work in another village. You decided to follow the straight path between your house (A) and the working place (B), but there are several rivers you need to cross. Assume B is to the right of A, and all…

题意:有两个盒子各有n个糖(n<=2*105),每天随机选1个(概率分别为p,1-p),然后吃掉一颗糖.直到有一天打开盒子一看,这个盒子没有糖了.输入n,p,求此时另一个盒子里糖的个数的数学期望. 思路:假设没糖的是A盒子,而B盒子还有0~n个糖.由于B盒子还有0个糖的情况的期望必为0,所以省略,只需要计算1~n的. (1)当A盒没有糖时,B盒就可能有1~n个糖,概率为C(n+i,i)*(pn+1)*(1-p)n-i.为啥还带个大C?这是情况的种数(想象取糖时还有个顺序,有C种可能的顺序),不然…

题目地址: http://acm.hdu.edu.cn/showproblem.php?pid=4336 题意简单,直接用容斥原理即可 AC代码: #include <iostream> #include <cstdio> #include <cstring> #include <string> #include <cstdlib> #include <cmath> #include <vector> #include &…