题目大意:3n个人围着一张桌子,给每个人发钱,可以使1块.2块.3块,第i个人的金额为Ai.若存在第个人使得Ai + Ai+n + Ai+2n != 6,则该分配方案满足条件,求所有的满足条件的方案数 结果 MOD 1000000007. 解题思路:当 n = 1 时有总共有27中情况,其中20中满足条件,则 (27^n - 7^n)为所求结果. 代码 #include<iostream> #include<cstdio> #include<cstdlib> using…

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…

Kolya got string s for his birthday, the string consists of small English letters. He immediately added k more characters to the right of the string. Then Borya came and said that the new string contained a tandem repeat of length l as a substring. H…

题目链接:http://codeforces.com/problemset/problem/584/B 解题思路:当n=1时,_______    _______   ______  三个数每位上可以填1,2,3三个数,所以,所有可能的结果就是3*3*3   不满足条件的有2 2 2这一种情况,还有1 2 3这三个数字,总共有6种情况,所以答案是27-1-6=20:当n=2时,所有可能的结果是3*3*3*3*3*3-?=680 ,可以推测出减去49即7*7 所以找到的规律就是: 当n=1时,  …

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…

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);…

---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…

链接:https://codeforces.com/contest/584 A - Olesya and Rodion - [水] 题解:注意到 $t$ 的范围是 $[2,10]$,对于位数小于 $2 \times 3 \times \cdots \times 10 = 3628800$ 的数,暴力枚举去找:否则就直接在 $3628800$ 后面补零即可. AC代码: #include<bits/stdc++.h> using namespace std; int n,t; ]; int ma…

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…

Tanya and Postcard time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Little Tanya decided to present her dad a postcard on his Birthday. She has already created a message — string s of lengt…