C. A and B and Team Training 题目:A and B are preparing themselves for programming contests. An important part of preparing for a competition is sharing programming knowledge from the experienced members to those who are just beginning to deal with the…

C. A and B and Team Training time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output A and B are preparing themselves for programming contests. An important part of preparing for a competition is s…

A and B and Team Training time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output A and B are preparing themselves for programming contests. An important part of preparing for a competition is shar…

C. A and B and Team Training time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output A and B are preparing themselves for programming contests. An important part of preparing for a competition is s…

题目链接:E. A and B and Lecture Rooms 题目大意 给定一颗节点数10^5的树,有10^5个询问,每次询问树上到xi, yi这两个点距离相等的点有多少个. 题目分析 若 x==y 直接返回 n. 先求出 x, y 两个点的中点. 先求出 LCA(x, y) = z,假设 Depth[x] >= Depth[y] ,若Depth[x] == Depth[y] ,那么 z 就是它们的中点. 答案就是,n - Size[fx] - Size[fy],fx 是从x向上跳,一直跳…

题目链接:D. A and B and Interesting Substrings 题目大意 给定26个小写字母的权值,一共26个整数(有正有负). 给定一个小写字母组成的字符串(长度10^5),求有多少长度大于1的子串满足: 1)首尾字符相同. 2)除了首尾字符外,其他字符的权值和为0. 题目分析 使用STL Map.开26个Map,给每个字母开一个. 先求出权值的前缀和 Sum[] . 然后1到l枚举每一位字符,如果是a,那么 Ans += Map[a][Sum[i - 1]]; 然后 +…

题目链接:http://codeforces.com/contest/519/problem/C 题目意思:给出 n 个  experienced participants  和 m 个 newbies ,需要组成尽量多的组,组由3个人组成.有两种组合方式:(1)1 个 experienced participant 和 2 个  newbie  (2)2 个 experienced participant 和 1 个  newbie.问最多能组成的组数是多少组. 昨天做的时候不是暴力做的,惯性…

题意 $a$个学生,$b$个教练 可以两个学生和一个教练一组,也可以两个教练和一个学生一组,问最多组成多少组 Sol 发题解的目的是为了纪念一下自己的错误思路 刚开始想的是:贪心的选,让少的跟多的分在一组里.事实证明这是错的,比如:500 500. 然后想的是:我们可以把教练和学生看着物品,密度最大应该是最优的,也就是$3$个教练和$3$个学生构成一组,但这样也是错的,比如7 11 又想了很久,发现我们根本就不用管他们是怎么分的,先特判掉$a < 2 * b$的情况,反正三个人一定能分成一组,那…

[链接] 我是链接,点我呀:) [题意] 在这里输入题意 [题解] 枚举第一种方法. 剩下的全都个第二种方法. 看看能组成多少个队伍就可以了. [代码] #include <bits/stdc++.h> #define ll long long using namespace std; int n,m; int main() { ios::sync_with_stdio(0),cin.tie(0); cin >> n >> m; int ans = 0; for(int…

水 A. A and B and Chess /* 水题 */ #include <cstdio> #include <algorithm> #include <iostream> #include <cstring> #include <string> using namespace std; const int maxn = 1e6 + 10; int a[maxn]; int main(void) { //freopen ("A.…