B. Kolya and Tanya Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/584/problem/B Description Kolya loves putting gnomes at the circle table and giving them coins, and Tanya loves studying triplets of gnomes, sitting in the v…

接近于死亡的选手没有水平更博客,所以现在每五个月更一篇. 这道题呢,首先如果已经有权限升级了,那么后面肯定全部选的是 \(p_ib_i\) 最高的. 设这个值为 \(M=\max \limits_i p_ib_i\). 主要的问题在于前面怎么选. 假设剩下的时间还有 \(t\) 秒.那么我们很容易得到一个这样的式子. \[ dp[t+1] = \max_i \{p_i \cdot (a_i+tM) + (1-p_i) \cdot dp[t]\} \] 把 \(\max\)里面的内容整理一下. \…

---恢复内容开始--- Codeforces Round #324 (Div. 2) Problem A 题目大意:给二个数n.t,求一个n位数能够被t整除,存在多组解时输出任意一组,不存在时输出“-1”. 数据范围: 1 ≤ n ≤ 100, 2 ≤ t ≤ 10 so easy!首先考虑无解的时候,只有当n==1,t==10是无解,其他情况都存在解.很容易想到最简单的n位数能被t整除的数是,t个n组成的数. 参考代码: By Royecode, contest: Codeforces Ro…

B. Kolya and Tanya time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Kolya loves putting gnomes at the circle table and giving them coins, and Tanya loves studying triplets of gnomes, sitting…

CF的rating设置改了..人太多了,决定开小号打,果然是明智的选择! 水 A - Olesya and Rodion #include <bits/stdc++.h> using namespace std; typedef long long ll; const int N = 1e5 + 10; const int INF = 0x3f3f3f3f; int main(void) { int n, t; scanf ("%d%d", &n, &t);…

原题链接:http://codeforces.com/contest/584/problem/B 题意: 有3*n个人围成一个圈,每个人可以分配1到3个硬币,但是相邻为n的三个人的和不能是6,问你有多少种方案 题解: 考虑反面,则答案是: $$27^n-(3!+1)^n$$ 代码: #include<iostream> #include<cstring> #include<cstdio> using namespace std; typedef long long LL…

题目链接:http://codeforces.com/contest/734/problem/C 题意: 玩一个游戏,一开始升一级需要t秒时间,现在有a, b两种魔法,两种魔法分别有m1, m2种效果: 对应使用a1[i]魔法需要a2[i]金币,使用b1[i]魔法需要b2[i]金币: 每种魔法最多只能使用一次,问升到n(n<=1e+5)级最少需要多少时间: 注意:给出的b1, b2数组是升序排列的: 思路:对每一个a魔法找到最大的b1魔法jj, 即为使用此a魔法需要最少时间的情况:再找到所有jj…

E. Anton and Ira Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/584/problem/E Description Anton loves transforming one permutation into another one by swapping elements for money, and Ira doesn't like paying for stupid game…

D. Dima and Lisa Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/584/problem/D Description Dima loves representing an odd number as the sum of multiple primes, and Lisa loves it when there are at most three primes. Help them…

C. Marina and Vasya Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/584/problem/C Description Marina loves strings of the same length and Vasya loves when there is a third string, different from them in exactly t characters.…