等比数列求和一定要分类讨论!!!!!!!!!!!! #include<bits/stdc++.h> #define LL long long #define fi first #define se second #define mk make_pair #define pii pair<int,int> #define ull unsigned long long using namespace std; ; +; const int inf=0x3f3f3f3f; const L…

Problem  Codeforces Round #556 (Div. 2) - D. Three Religions Time Limit: 1000 mSec Problem Description Input Output Sample Input 51 2 1 2 1 Sample Output 1 1 1 2 2 题解:这个题有做慢了,这种题做慢了和没做出来区别不大... 读题的时候脑子里还意识到素数除了2都是奇数,读完之后就脑子里就只剩欧拉筛了,贪心地构造使得前缀和是连续的素数,那…

A - Splits 题意 将一个正整数拆分成若干个正整数的和,从大到小排下来,与第一个数字相同的数字的个数为这个拆分的权重. 问\(n\)的所有拆分的不同权重可能个数. 思路 全拆成1,然后每次将2个1换成1个2,即每次2的个数增加1. 共有1+n/2种. Code #include <bits/stdc++.h> #define F(i, a, b) for (int i = (a); i < (b); ++i) #define F2(i, a, b) for (int i = (a…

A. Splits time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Let's define a split of n as a nonincreasing sequence of positive integers, the sum of which is n. For example, the following seque…

A. Alternating Sum 就是个等比数列,特判公比为 $1$ 的情况即可. #include <bits/stdc++.h> using namespace std; ; ; ) { ; while (b) { ) ans = 1LL * ans * a % MOD; a = 1LL * a * a % MOD; b >>= ; } return ans; } int M(int a) { ) a += MOD; if (a >= MOD) a -= MOD; r…

B. Alternating Current Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/343/problem/B Description Mad scientist Mike has just finished constructing a new device to search for extraterrestrial intelligence! He was in such a hu…

B. Modulo Sum Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/577/problem/B Description You are given a sequence of numbers a1, a2, ..., an, and a number m. Check if it is possible to choose a non-empty subsequence aij such…

E. Product Sum 题目连接: http://www.codeforces.com/contest/631/problem/E Description Blake is the boss of Kris, however, this doesn't spoil their friendship. They often gather at the bar to talk about intriguing problems about maximising some values. Thi…

D. Alternating Current time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Mad scientist Mike has just finished constructing a new device to search for extraterrestrial intelligence! He was in…

 传送门 Description Little Chris is very keen on his toy blocks. His teacher, however, wants Chris to solve more problems, so he decided to play a trick on Chris. There are exactly s blocks in Chris's set, each block has a unique number from 1 to s. Chr…