D. Unbearable Controversy of Being time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Tomash keeps wandering off and getting lost while he is walking along the streets of Berland. It's no surp…

Unbearable Controversy of Being 题目链接: http://acm.hust.edu.cn/vjudge/contest/121332#problem/B Description Tomash keeps wandering off and getting lost while he is walking along the streets of Berland. It's no surprise! In his home town, for any pair of…

题意: 给出一个n个节点m条边的有向图,求如图所示的菱形的个数. 这四个节点必须直接相邻,菱形之间不区分节点b.d的个数. 分析: 我们枚举每个a和c,然后求出所有满足a邻接t且t邻接c的节点的个数记为r. 那么分别以a.c为左右端点的菱形的个数就是r的二元组合. #include <cstdio> #include <vector> using namespace std; + ; bool G[maxn][maxn]; vector<int> nxt[maxn];…

http://codeforces.com/problemset/problem/1009/B B. Minimum Ternary String time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You are given a ternary string (it is a string which consists only…

题目传送门:http://codeforces.com/contest/957/problem/D 题意大致是这样的:有一个水池,每天都有一个水位(一个整数).每天都会在这一天的水位上划线(如果这个水位已经被划线了,那么不划线). 现在告诉你每天能看见的线条mi(就是高于水面的,刚好在水面的不算),设di为第i天水面以下的线条数(刚好在水面的不算),求(d1+d2+d3....dn)的最小值. 解析: 我们设第i天有ki条水位线,容易得到: 移项后,将d留在右边,我们发现mi和n都是固定的,所以…

C. Meaningless Operations time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Can the greatest common divisor and bitwise operations have anything in common? It is time to answer this question.…

E. Vanya and Field time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Vanya decided to walk in the field of size n × n cells. The field contains m apple trees, the i-th apple tree is at the c…

http://codeforces.com/problemset/problem/489/D D. Unbearable Controversy of Being time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Tomash keeps wandering off and getting lost while he is wal…

除非特别忙,我接下来会尽可能翻译我做的每道CF题的题面! Codeforces 148D 一袋老鼠 Bag of mice | 概率DP 水题 题面 胡小兔和司公子都认为对方是垃圾. 为了决出谁才是垃圾,大哥拿来了一袋老鼠,其中有w只白老鼠和b只黑老鼠.胡小兔先抓,先抓到白老鼠的人赢. 每次学姐抓完老鼠之后,总会有另外一只老鼠从袋子里自己跑出来(这只老鼠不算任何人抓的),而胡小兔抓老鼠时则不会发生这样的事. 每次袋子里的每只老鼠被抓到的概率相等,当有一只老鼠跑出来的时候,每只老鼠跑出来的几率也相…

题目传送门 /* 题意:套娃娃,可以套一个单独的娃娃,或者把最后面的娃娃取出,最后使得0-1-2-...-(n-1),问最少要几步 贪心/思维题:娃娃的状态:取出+套上(2),套上(1), 已套上(0),先从1开始找到已经套好的娃娃层数, 其他是2次操作,还要减去k-1个娃娃是只要套上就可以 详细解释:http://blog.csdn.net/firstlucker/article/details/46671251 */ #include <cstdio> #include <algor…

这场比赛没有打,后来补了一下,第五题数位dp好不容易才搞出来(我太菜啊). 比赛传送门:http://codeforces.com/contest/1073 A. Diverse Substring 题意:给你个字符串,让你找一个子串满足任意一个字符的个数不超过其他字符的总和,输出yes或no表示否存在,如果存在输出任意一个. 这题只要找两个不同的相邻字符,因为两个字符各一个都不超过其他字符的总和,如果字符串只由一个字符组成或长度等于一才会不存在. 代码如下: #include <iostrea…

[链接] 我是链接,点我呀:) [题意] 让你找到(a,b,c,d)的个数 这4个点之间有4条边有向边 (a,b)(b,c) (a,d)(d,c) 即有两条从a到b的路径,且这两条路径分别经过b和d到达c [题解] 我们枚举a,c 然后找到这样的b的个数cntb,其中a到b有一条边,b到c也有一条边 显然从这cntb个b中取2个 就能组成b和d了. 即C(N,2) 怎么得到这样的b的个数呢 先枚举a的所有出点v,然后看看v是否和c联通即可. 联通的话,cntb++ [代码] import jav…

这道题我临场想到了枚举菱形的起点和终点,然后每次枚举起点指向的点,每个指向的点再枚举它指向的点看有没有能到终点的,有一条就把起点到终点的路径个数加1,最后ans+=C(路径总数,2).每两个点都这么弄.但是我考虑时间复杂度n2前面的系数过大会超时,再想别的方法也没想出来.. 其实思路就是这样的,只不过时间上可以优化一下,就是用常用的两种做法不变而优化时间复杂度的方法:1.以空间换时间2.分步降维 #include <cstdio> #include <vector> using n…

http://codeforces.com/contest/489/problem/D 很显然,我们只需要找对于每个点能到达的深度为3的点的路径的数量,那么对于一个深度为3的点,如果有a种方式到达,那么有方案数(a-1+1)*(a-1)/2 可是我用dfs找路径就tle了QAQ 于是orz别人的代码,,,,是暴力........................直接两重循环orz #include <cstdio> #include <cstring> #include <cm…

题目大意:求有向图中这种图的数量 从分层图来考虑,这是一个层数为3的图 枚举第一个点能到达的所有点,对他们进行BFS求第三层的点(假装它是BFS其实直接枚举效果一样) 代码: #include<iostream> #include<cstdio> #include<cstring> #include<queue> #define ll long long #define M 100010 using namespace std; struct point{…

原题:http://codeforces.com/contest/675/problem/C 让我们用数组a保存每个银行的余额,因为所有余额的和加起来一定为0,所以我们能把整个数组a划分为几个区间,每个区间的和都为0.对于每个区间来说,设该区间长度为l,则让该区间都为0的操作数为l-1,例如:1 .1 .-3 .1的操作数为3,也就是说,若把a分成k个区间,则a所需要的总的操作数为n-k. 所以现在我们的目标就是把数组a划分为尽可能多的部分,这个时候我们可以用一个map,统计前缀和的个数,因为对…

C. Vladik and fractions 题目链接 http://codeforces.com/contest/743/problem/C 题面 Vladik and Chloe decided to determine who of them is better at math. Vladik claimed that for any positive integer n he can represent fraction as a sum of three distinct posit…

A. Vladik and flights 题目链接 http://codeforces.com/contest/743/problem/A 题面 Vladik is a competitive programmer. This year he is going to win the International Olympiad in Informatics. But it is not as easy as it sounds: the question Vladik face now is…

D. Anton and Chess 题目连接: http://codeforces.com/contest/734/problem/D Description Anton likes to play chess. Also, he likes to do programming. That is why he decided to write the program that plays chess. However, he finds the game on 8 to 8 board to…

B. Anton and Digits 题目连接: http://codeforces.com/contest/734/problem/B Description Recently Anton found a box with digits in his room. There are k2 digits 2, k3 digits 3, k5 digits 5 and k6 digits 6. Anton's favorite integers are 32 and 256. He decide…

A. Anton and Danik 题目连接: http://codeforces.com/contest/734/problem/A Description Anton likes to play chess, and so does his friend Danik. Once they have played n games in a row. For each game it's known who was the winner - Anton or Danik. None of th…

Police Recruits Time Limit: 1000MS   Memory Limit: 262144KB   64bit IO Format: %I64d & %I64u Submit Status Description The police department of your city has just started its journey. Initially, they don’t have any manpower. So, they started hiring n…

Squats Time Limit: 1000MS   Memory Limit: 262144KB   64bit IO Format: %I64d & %I64u Submit Status Description Pasha has many hamsters and he makes them work out. Today, n hamsters (n is even) came to work out. The hamsters lined up and each hamster e…

题目链接:http://codeforces.com/problemset/problem/328/B 水题~ #include <cstdio> #include <cstdlib> #include <cstring> ], a[]; ], c[]; int main(void) { //freopen("in.txt", "r", stdin); scanf("%s%s", n, a); int len1…

题目链接:http://codeforces.com/problemset/problem/616/E 题意很简单就不说了. 因为n % x = n - n / x * x 所以答案就等于 n * m - (n/1*1 + n/2*2 ... n/m*m) 在根号n复杂度枚举x,注意一点当m>n时,后面一段加起来就等于0,就不用再枚举了. 中间一段x1 ~ x2 的n/x可能相等,所以相等的一段等差数列求和. //#pragma comment(linker, "/STACK:102400…

B. Gena's Code 题目连接: http://www.codeforces.com/contest/614/problem/B Description It's the year 4527 and the tanks game that we all know and love still exists. There also exists Great Gena's code, written in 2016. The problem this code solves is: give…

A. Link/Cut Tree 题目连接: http://www.codeforces.com/contest/614/problem/A Description Programmer Rostislav got seriously interested in the Link/Cut Tree data structure, which is based on Splay trees. Specifically, he is now studying the expose procedure…

A. New Year and Days 题目连接: http://www.codeforces.com/contest/611/problem/A Description Today is Wednesday, the third day of the week. What's more interesting is that tomorrow is the last day of the year 2015. Limak is a little polar bear. He enjoyed…

A. Fox And Snake 题目连接: http://codeforces.com/contest/510/problem/A Description Fox Ciel starts to learn programming. The first task is drawing a fox! However, that turns out to be too hard for a beginner, so she decides to draw a snake instead. A sna…

A. Saitama Destroys Hotel 题目连接: http://www.codeforces.com/contest/608/problem/A Description Saitama accidentally destroyed a hotel again. To repay the hotel company, Genos has volunteered to operate an elevator in one of its other hotels. The elevato…