题意: 有一道分值为sa的题,n个人比赛写这道题,按照递减的顺序给出每个人的当前分数,和每个人写不出这道题的概率,让你输出有反超现象出现的期望 思路:由于之前把题目翻译错了导致很久没有相通,后来看了别人的博客和代码才理解了这道题 http://blog.csdn.net/richie_ll/article/details/57088108 首先我们先看一下什么是数学期望:试验中每次结果可能的概率乘以其结果的总和,再回过头来看这道题,让你求出有反超现象出现的期望,其实也是在求反超现象出现的概率(可…

http://codeforces.com/gym/101257/problem/GGym 101257G 题意:给出n个人,和一个数s,接下来给出每个人当前的分数和输掉的概率.当一个人输了之后就会掉s分.求第i个人当前的分数大于第j个人当前的分数并且比赛结束后第i个人的分数小于第j个人的(i,j)对数的期望. 思路:用尺取的做法,r指针在前面,l指针在后面,从后往前扫,记录一个前缀和lose,代表前面r指针遇到的人输的概率,当扫到valr - s >= vall的时候停止r,让l往左扫,期间l…

题目链接 http://codeforces.com/problemset/gymProblem/100703/I Description standard input/outputStatements As a matter of fact, Dragon knows what Prince is interested in now. Prince uses to spend his rare off days learning different courses and trainings.…

King George has recently decided that he would like to have a new design for the royal graveyard. The graveyard must consist of several sections, each of which must be a square of graves. All sections must have different number of graves. After a con…

Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representations does a given positive integer have? For example, the integer 53 has two representations 5 + 7 + 11 + 13 + 17 and 53…

Graveyard Design Time Limit: 10000MS Memory Limit: 64000K Total Submissions: 8504 Accepted: 2126 Case Time Limit: 2000MS Description King George has recently decided that he would like to have a new design for the royal graveyard. The graveyard must…

Problem 1072: The longest same color grid Time Limits:  1000 MS   Memory Limits:  65536 KB 64-bit interger IO format:  %lld   Java class name:  Main Description There are n grid, m kind of color. Grid number 1 to N, color number 1 to M.  The color of…

Bob’s Race Time Limit: 5000/2000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Problem Description Bob wants to hold a race to encourage people to do sports. He has got trouble in choosing the route. There are N houses and N - 1 roads…

题目链接:http://codeforces.com/problemset/problem/180/E 给你n个数,每个数代表一种颜色,给你1到m的m种颜色.最多可以删k个数,问你最长连续相同颜色的序列的长度是多少. 将相同颜色的下标存到对应颜色的容器中,比如ans[a[i]].push_back(i)就是将下标为i颜色为a[i]的数存到ans[a[i]]容器中. 对于每种颜色序列,尺取一下 在差距小于k的情况下取能取到的最大长度. //#pragma comment(linker, "/STA…

Signals of most probably extra-terrestrial origin have been received and digitalized by The Aeronautic and Space Administration (that must be going through a defiant phase: "But I want to use feet, not meters!"). Each signal seems to come in two…