链接:http://codeforces.com/contest/454/problem/A A. Little Pony and Crystal Mine time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Twilight Sparkle once got a crystal from the Crystal Mine. A c…

A. Little Pony and Expected Maximum Time Limit: 1 Sec  Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/453/problem/A Description Twilight Sparkle was playing Ludo with her friends Rainbow Dash, Apple Jack and Flutter Shy. But she kept losing.…

A. Little Pony and Crystal Mine 水题,每行D的个数为1,3.......n-2,n,n-2,.....3,1,然后打印即可 #include <iostream> #include <vector> #include <algorithm> #include <string> using namespace std; int main(){ int n; cin >> n; vector<string>…

题目范围给的很小,所以有状压的方向. 我们是构造出一个数列,且数列中每两个数的最大公约数为1; 给的A[I]<=30,这是一个突破点. 可以发现B[I]中的数不会很大,要不然就不满足,所以B[I]<=60左右.构造DP方程DP[I][J]=MIN(DP[I][J],DP[I][J^C[K]]+abs(a[i]-k)); K为我们假设把这个数填进数组中的数.同时开相同空间记录位置,方便输出结果.. #include<iostream> #include<stdio.h>…

题目链接 题意 : 一个m面的骰子,掷n次,问得到最大值的期望. 思路 : 数学期望,离散时的公式是E(X) = X1*p(X1) + X2*p(X2) + …… + Xn*p(Xn) p(xi)的是所有最大值是xi的情况数/总情况数一共是m^n种,掷n次,所有最大值是xi的情况数应该是xi^n,但是这里边却包含着最大值非xi且不超过xi的种数,所以再减去最大值是xi-1或者最大值不超过这个的情况数.即sum += xi * (xi^n-(xi-1)^n)/m^n,但是这样求肯定是不行,因为m…

题目链接 题意:一个m个面的骰子,抛掷n次,求这n次里最大值的期望是多少.(看样例就知道) 分析: m个面抛n次的总的情况是m^n, 开始m==1时,只有一种 现在增加m = 2,  则这些情况是新增的那个的第一次的结果的后面最大的都是新增的, 之前的这些的分支也加上这个数,而且这个数是这一支里最大的,也就是说新增产生的结果 全都是m = 2的这个结果,所以用现在的总的情况减去之前的总的情况. 所以: 最大值是1: 1种 2: 2^n-1 3: 3^n-2^n ..... m: m^n-(m-1…

D. Little Pony and Harmony Chest   Princess Twilight went to Celestia and Luna's old castle to research the chest from the Elements of Harmony. A sequence of positive integers bi is harmony if and only if for every two elements of the sequence their…

传送门 题意 给出m个面的骰子扔n次,取最大值,求期望 分析 暴力算会有重复,而且复杂度不对. 考虑m个面扔n次得到m的概率,发现只要减去(m-1)个面扔n次得到m-1的概率即可,给出example说明 n=2 m=6 6 6 6 6 6 6 5 5 5 5 5 6 4 4 4 4 5 6 3 3 3 4 5 6 2 2 3 4 5 6 1 2 3 4 5 6 得到公式 \[\sum_{i=1}^m{i*(i^n-(i-1)^n)/m^n}\] 代码 #include <bits/stdc++.…

D. Little Pony and Harmony Chest time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output Princess Twilight went to Celestia and Luna's old castle to research the chest from the Elements of Harmony…

Codeforces Round #366 (Div. 2) A I hate that I love that I hate it水题 #I hate that I love that I hate it n = int(raw_input()) s = "" a = ["I hate that ","I love that ", "I hate it","I love it"] for i in ran…