A - Play the DiceTime Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://acm.hust.edu.cn/vjudge/contest/view.action?cid=87326#problem/A Description There is a dice with n sides, which are numbered from 1,2,...,n and have the equal possibility to show up…

题意:给定三个表达式,问你求出最小的m1,m2,满足G(m1) >= F(n), G(m2) >= G(n). 析:这个题是一个概率DP,但是并没有那么简单,运算过程很麻烦. 先分析F(n),这个用DP来推公式,d[i],表示抛 i 次连续的点数还要抛多少次才能完成.那么状态转移方程就是 d[i] = 1/6*(1+d[i+1]) + 5/6*(1+d[1]), 意思就是说在第 i 次抛和上次相同的概率是1/6,然后加上上次抛的和这一次,再加上和上次不同的,并且又得从第1次开始计算. 边界就是…

ATM Mechine 题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=5781 Description Alice is going to take all her savings out of the ATM(Automatic Teller Machine). Alice forget how many deposit she has, and this strange ATM doesn't support query deposit. T…

Aeroplane chess Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 1503    Accepted Submission(s): 1025 Problem Description Hzz loves aeroplane chess very much. The chess map contains N+1 grids la…

C - Throwing Dice Time Limit:2000MS     Memory Limit:32768KB     64bit IO Format:%lld & %llu LightOJ 1064 uDebug Description n common cubic dice are thrown. What is the probability that the sum of all thrown dice is at least x? Input Input starts wit…

wolf5x Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 402    Accepted Submission(s): 248 Special Judge Problem Description There are n grids in a row. The coordinates of grids are numbered fro…

///题意: /// A,B掷骰子,对于每一次点数大者胜,平为和,A先胜了m次A赢,B先胜了n次B赢. ///p1表示a赢,p2表示b赢,p=1-p1-p2表示平局 ///a赢得概率 比一次p1 两次p0*p1 三次 p0^2*p1,即A赢的概率为p1+p*p1+p^2*p1+...p^n*p1,n->无穷 ///即a_win=p1/(1-p);b_win=p2/(1-p); ///dp[i][j]表示a赢了j次,b赢了i次的概率 ///dp[i][j]=dp[i-1][j]*b_win+dp[…

Card Collector Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3407    Accepted Submission(s): 1665Special Judge Problem Description In your childhood, do you crazy for collecting the beautiful…

题意: 一个骰子,n个面,摇到每一个面的概率都一样.问你把每一个面都摇到至少一次需要摇多少次,求摇的期望次数 题解: dp[i]:已经摇到i个面,还需要摇多少次才能摇到n个面的摇骰子的期望次数 因为我们只知道dp[n]的值,所以我们只能倒推,dp[n]=0(感觉大部分概率dp都是倒推~~~~) dp[i]=i/n*dp[i]+(n-i)/ndp[i+1]+1 化简一下: dp[i]=dp[i+1]+n/(n-i) 代码: #include<stdio.h> #include<string…

Problem Description There is a dice with n sides, which are numbered from 1,2,...,n and have the equal possibility to show up when one rolls a dice. Each side has an integer ai on it. Now here is a game that you can roll this dice once, if the i-th s…