Codeforces Round #500 (Div. 2) [based on EJOI] https://codeforces.com/contest/1013 A #include<bits/stdc++.h> using namespace std; #define lson l,mid,rt<<1 #define rson mid+1,r,rt<<1|1 #define IT set<node>::iterator #define sqr(x) (…

Codeforces Round #403 (Div. 2, based on Technocup 2017 Finals) 说一点东西: 昨天晚上$9:05$开始太不好了,我在学校学校$9:40$放学我呆到十点然后还要跑回家耽误时间....要不然$D$题就写完了 周末一些成绩好的同学单独在艺术楼上课然后晚上下第一节晚自习和他们在回廊里玩开灯之后再关上一片漆黑真好玩 A.Andryusha and Socks 日常煞笔提.....我竟然$WA$了一次忘了$n<<1$ #include <…

Codeforces Round #517 (Div. 2, based on Technocup 2019 Elimination Round 2) #include <bits/stdc++.h> using namespace std; int n,m,k; ; int main() { cin>>n>>m>>k; ;i<=k-;++i) { sum+=(n+(m-))*-(i)*; } cout<<sum<<endl;…

A. Even Subset Sum Problem 题意 给出一串数,找到其中的一些数使得他们的和为偶数 题解 水题,找到一个偶数或者两个奇数就好了 代码 #include<iostream> #include<cstdio> #include<cstring> #define def 110 using namespace std; long a[def]; int main() { long _,ans0,ans1,ans2,n,i; for(scanf(&quo…

A - Forgetting Things 题意:给 \(a,b\) 两个数字的开头数字(1~9),求使得等式 \(a=b-1\) 成立的一组 \(a,b\) ,无解输出-1. 题解:很显然只有 \(a=b\) 和 \(a=b-1\) 的时候有解,再加上一个从 \(9\) 越到 \(10\) 的就可以了.被样例的 \(199,200\) 误导了. #include<bits/stdc++.h> using namespace std; typedef long long ll; int mai…

A. Right-Left Cipher time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Polycarp loves ciphers. He has invented his own cipher called Right-Left. Right-Left cipher is used for strings. To encr…

比赛传送门 只能说当晚状态不佳吧,有点头疼感冒的症状.也跟脑子没转过来有关系,A题最后一步爆搜没能立即想出来,B题搜索没有用好STL,C题也因为前面两题弄崩了心态,最后,果然掉分了. A:简单数学 B:数学+排序 C:字符串搜索 A // https://codeforces.com/contest/1277/problem/A /* 题意: 给出一个数,求不大于该数的完美整数的个数(完美整数指全是一个数组成的数字,如:111, 333333, 444444, 9, 8888 ...) 分析:…

C. Did you mean... time limit per test:1 second memory limit per test:256 megabytes input:standard input output:standard output Beroffice text editor has a wide range of features that help working with text. One of the features is an automatic search…

B. Which floor? time limit per test:1 second memory limit per test:256 megabytes input:standard input output:standard output In a building where Polycarp lives there are equal number of flats on each floor. Unfortunately, Polycarp don't remember how…

A. k-rounding time limit per test:1 second memory limit per test:256 megabytes input:standard input output:standard output For a given positive integer n denote its k-rounding as the minimum positive integer x, such that x ends with k or more zeros i…