E. Tree Folding 题目连接: http://codeforces.com/contest/765/problem/E Description Vanya wants to minimize a tree. He can perform the following operation multiple times: choose a vertex v, and two disjoint (except for v) paths of equal length a0 = v, a1,…

地址:http://codeforces.com/contest/765/problem/E 题目: E. Tree Folding time limit per test 2 seconds memory limit per test 512 megabytes input standard input output standard output Vanya wants to minimize a tree. He can perform the following operation mu…

F. Souvenirs 题目连接: http://codeforces.com/contest/765/problem/F Description Artsem is on vacation and wants to buy souvenirs for his two teammates. There are n souvenir shops along the street. In i-th shop Artsem can buy one souvenir for ai dollars, a…

D. Artsem and Saunders 题目连接: http://codeforces.com/contest/765/problem/D Description Artsem has a friend Saunders from University of Chicago. Saunders presented him with the following problem. Let [n] denote the set {1, ..., n}. We will also write f:…

C. Table Tennis Game 2 题目连接: http://codeforces.com/contest/765/problem/C Description Misha and Vanya have played several table tennis sets. Each set consists of several serves, each serve is won by one of the players, he receives one point and the lo…

B. Code obfuscation 题目连接: http://codeforces.com/contest/765/problem/B Description Kostya likes Codeforces contests very much. However, he is very disappointed that his solutions are frequently hacked. That's why he decided to obfuscate (intentionally…

A. Neverending competitions 题目连接: http://codeforces.com/contest/765/problem/A Description There are literally dozens of snooker competitions held each year, and team Jinotega tries to attend them all (for some reason they prefer name "snookah")!…

A. Neverending competitions time limit per test 2 seconds memory limit per test 512 megabytes input standard input output standard output There are literally dozens of snooker competitions held each year, and team Jinotega tries to attend them all (f…

地址:http://codeforces.com/contest/765/problem/D 题目: D. Artsem and Saunders time limit per test 2 seconds memory limit per test 512 megabytes input standard input output standard output Artsem has a friend Saunders from University of Chicago. Saunders…

地址:http://codeforces.com/contest/765/problem/C 题目: C. Table Tennis Game 2 time limit per test 2 seconds memory limit per test 512 megabytes input standard input output standard output Misha and Vanya have played several table tennis sets. Each set co…

地址:http://codeforces.com/contest/765/problem/B 题目: B. Code obfuscation time limit per test 2 seconds memory limit per test 512 megabytes input standard input output standard output Kostya likes Codeforces contests very much. However, he is very disap…

地址:http://codeforces.com/contest/765/problem/A 题目: A. Neverending competitions time limit per test 2 seconds memory limit per test 512 megabytes input standard input output standard output There are literally dozens of snooker competitions held each…

Description Kostya likes Codeforces contests very much. However, he is very disappointed that his solutions are frequently hacked. That's why he decided to obfuscate (intentionally make less readable) his code before upcoming contest. To obfuscate th…

运气好,分到的房里我最先开始Hack C题,Hack了12个,听说F题沙雕莫队但我不会,最后剩不到15分钟想出E题做法打了一波结果挂了,最后虽然上分了但总有点不甘心. 最后A掉ABCD Hack+12 Rank:176 Rating:2109+47->2156 上次被黄学长D:"怎么说你也有2200了吧",2100蒟蒻真是抱歉QAQ A.Neverending competitions 题目大意:某人从家里飞出去再飞回来再飞出去再飞回来--,现在给你N张他用过的机票(N<=…

根据那两个式子 g(h(x))=x h(g(x))=f(x) 可以推出来两个新的式子 g(f(x))=g(x) h(x)=f(h(x)) 于是,我们先找到f(x)的所有不动点,有几个不动点,m就是多少,将它们依次赋值给h(1),h(2),...,h(m),对应的g(h(i))赋值成1,2,..,m 然后如果对于某个i,g(f(i))不存在的话,则无解,否则有解,将g和h依次输出即可. #include<cstdio> using namespace std; int n,f[100010],g…

Misha and Vanya have played several table tennis sets. Each set consists of several serves, each serve is won by one of the players, he receives one point and the loser receives nothing. Once one of the players scores exactly k points, the score is r…

Description There are literally dozens of snooker competitions held each year, and team Jinotega tries to attend them all (for some reason they prefer name "snookah")! When a competition takes place somewhere far from their hometown, Ivan, Artse…

http://codeforces.com/problemset/problem/765/D 题意: 有一个函数f,f: [n] → [n] 的意思就是定义域为[1,n],每个x值对应于[1,n]内的一个值(后面的意思也是如此).现在确定是否存在这样的一个m以及函数h和g,使得满足上述要求. 思路: 对于h(g(x)) = f(x) ,因为x属于[1,n],所欲f函数的所有值h函数都要包括,既然如此的话,那么f函数中有多少个不同的值,那么m的值就是多大,只需要让h(1),h(2)...依次等于这…

Problem A. Neverending competitions 题目大意 一个团队有多个比赛,每次去比赛都会先订机票去比赛地点,然后再订机票返回.给出\(n\)个含有起止地点的购票记录(不按时间顺序),判断这个团队是否返回. 题解 竞速题 因为每次比赛都必定是一去一返 所以当订票记录个数为偶数的时候一定在家中,否则一定在比赛. Code a = input() if a % 2 == 0: print 'home' else: print 'contest' Problem B. Cod…

题目链接:https://codeforces.com/contest/1100/problem/E 题意:给出 n 个点 m 条边的有向图,要翻转一些边,使得有向图中不存在环,问翻转的边中最大权值最小是多少. 题解:首先要二分权值,假设当前最大权值是 w,那么大于 w 的边一定不能翻转,所以大于 w 所组成的有向图不能有环,而剩下小于等于 w 的边一定可以构造出一个没有环的图(因为如果一条边正反插入都形成环的话,那么图里之前已经有环了),构造方法是把大于 w 的边跑拓扑序,然后小于等于 w 的…

先做拓扑排序,再bfs处理 #include<cstdio> #include<iostream> #include<cstdlib> #include<cstring> #include<, INF = , , ; } ;i<=n; i++) {         ) {             st.push(i);         }     }     ;         ; i = edge[i].next){             ;…

题意: 一棵树,给出每个点的后代们,问你这棵树是否存在,存在就给出这棵树 n<=1000 思路: 对祖先->后代建立有向图,跑拓扑排序.跑的时候不断更新父亲并判断答案的存在性,同时注意一种情况:一个点他儿子是他的后代,同样也得是他父亲的后代,这样传递下去就一定是所有祖宗的后代. 代码: 代码参考网上的 #include<iostream> #include<cstdio> #include<algorithm> #include<cmath> #…

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 #366 (Div. 2) A I hate that I love that I hate it水题 #I hate that I love that I hate it n = int(raw_input()) s = "" a = ["I hate that ","I love that ", "I hate it","I love it"] for i in ran…

Codeforces Round #354 (Div. 2) Problems     # Name     A Nicholas and Permutation standard input/output 1 s, 256 MB    x3384 B Pyramid of Glasses standard input/output 1 s, 256 MB    x1462 C Vasya and String standard input/output 1 s, 256 MB    x1393…

直达–>Codeforces Round #368 (Div. 2) A Brain’s Photos 给你一个NxM的矩阵,一个字母代表一种颜色,如果有”C”,”M”,”Y”三种中任意一种就输出”#Color”,如果只有”G”,”B”,”W”就输出”#Black&White”. #include <cstdio> #include <cstring> using namespace std; const int maxn = 200; const int INF =…

 cf之路,1,Codeforces Round #345 (Div. 2) ps:昨天第一次参加cf比赛,比赛之前为了熟悉下cf比赛题目的难度.所以做了round#345连试试水的深浅.....       其实这个应该是昨天就写完的,不过没时间了,就留到了今天.. 地址:http://codeforces.com/contest/651/problem/A A. Joysticks time limit per test 1 second memory limit per test 256…

Codeforces Round #279 (Div. 2) 做得我都变绿了! Problems     # Name     A Team Olympiad standard input/output 1 s, 256 MB  x2377 B Queue standard input/output 2 s, 256 MB  x1250 C Hacking Cypher standard input/output 1 s, 256 MB  x740 D Chocolate standard in…

Codeforces Round #262 (Div. 2) 1003 C. Present time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Little beaver is a beginner programmer, so informatics is his favorite subject. Soon his info…

Codeforces Round #262 (Div. 2) 1004 D. Little Victor and Set time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Little Victor adores the sets theory. Let us remind you that a set is a group of…