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 that each ball has equal probability of going to each boxes. After the experiment,…

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

题意:给2组数据a和b数组,每次有2种操作:(+,l,r,x)把a数组第l个到第r个元素全置为x,(?,l,r)查询[l,r]之间哪些位置满足a[i]>=b[i](i>=l && i<=r)并把这些位置的数量统计 一直想很久,没想到什么有效的方案,直到看到题解才明白过来,原来线段树套平衡树还有这种情况:里面其实不是平衡树,只是有序表. 然后这题就转换为区间查找数对应排名 由于此题不用对2个数组都修改,其中1个b树可作为固定的线段树套有序表以节省时间,另外1个表a树则单纯使…

Being an ACMer requires knowledge in many fields, because problems in this contest may use physics, biology, and even musicology as background. And now in this problem, you are being a city architect! A city with N towns (numbered 1 through N) is und…

A stack is a data structure in which all insertions and deletions of entries are made at one end, called the "top" of the stack. The last entry which is inserted is the first one that will be removed. In another word, the operations perform in a…

这题似乎就是纯概率论.. E(V)=D(X_i)=npq (p=1/m,p+q=1) #include<bits/stdc++.h> using namespace std; typedef long long LL; LL n,m; LL gcd(LL a,LL b) { return b?gcd(b,a%b):a; } int main() { while(cin>>n>>m && n+m) { LL a=n*m-n,b=m*m; LL g=gcd(…

题目链接 这题似乎就是纯概率论.. E(V)=D(X_i)=npq (p=1/m,p+q=1) #include<bits/stdc++.h> using namespace std; typedef long long LL; LL n,m; LL gcd(LL a,LL b) { return b?gcd(b,a%b):a; } int main() { while(cin>>n>>m && n+m) { LL a=n*m-n,b=m*m; LL g…

Balls and Boxes 题目链接: 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…

Balls and Boxes                                                                            Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)                                                                            …

Balls and Boxes Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 260    Accepted Submission(s): 187 Problem Description Mr. Chopsticks is interested in random phenomena, and he conducts an experi…