E. Strictly Positive Matrix   You have matrix a of size n × n. Let's number the rows of the matrix from 1 to n from top to bottom, let's number the columns from 1 ton from left to right. Let's use aij to represent the element on the intersection of t…

题目:http://codeforces.com/contest/402/problem/E 题意:给你一个矩阵a,判断是否存在k,使得a^k这个矩阵全部元素都大于0 分析:把矩阵当作01矩阵,超过1的都当作1,那么a矩阵可表示一个有向图的走一次的连通性,则a^k表示有向图走K次的连通性.既然要求最后都没0,即走了K次后,每个点都能互通,这也说明这个图必然是只有一个强联通分量.于是判断k的存在有无,也就是判断a矩阵表示的有向图是不是只有一个强联通分量.…

题目地址 /* 题意:要你构造一个有2n+p条边的图,使得,每一个含k个结点子图中,最多有2*k+p条边 水得可以啊,每个点向另外的点连通,只要不和自己连,不重边就可以,正好2*n+p就结束:) */ #include <cstdio> #include <iostream> #include <algorithm> #include <cstring> #include <string> #include <map> #includ…

题目传送门 /* 贪心:每一次选取最多的线段,最大能放置nuts,直到放完为止,很贪婪! 题目读不懂多读几遍:) */ #include <cstdio> #include <algorithm> #include <cstring> #include <cmath> using namespace std; ; const int INF = 0x3f3f3f3f; int main(void) //Codeforces Round #236 (Div.…

A. Nuts time limit per test:1 secondmemory limit per test:256 megabytesinput:standard inputoutput:standard output You have a nuts and lots of boxes. The boxes have a wonderful feature: if you put x (x ≥ 0) divisors (the spacial bars that can divide a…

链接:https://codeforces.com/contest/1130/problem/A 题意: 给n个数,找出一个非0整数d,使所有n个数除以整数d后,数组中正数的数量>= n/2. 如果不存在d,输出0. 思路: 记录正数和负数的数量,只有有一个满足就输出1或-1,否则为0. 代码: #include <bits/stdc++.h> using namespace std; typedef long long LL; int main() { int n, a; cin &g…

题目大意 我们说一个无向图是 p-interesting 当且仅当这个无向图满足如下条件: 1. 该图恰有 2 * n + p 条边 2. 该图没有自环和重边 3. 该图的任意一个包含 k 个节点的子图含有不超过 2 * k + p 条边 现在,请你找出一个 p-interesting 包含 n 个节点的无向图,输出他的 2 * n + p 条边 数据范围:5 ≤ n ≤ 24,0 ≤ p, 2 * n + p ≤ (n) * (n + 1) / 2 做法分析 好久没有做题了,刷刷水题练练手 第…

B. OR in Matrix Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/486/problem/B Description Let's define logical OR as an operation on two logical values (i. e. values that belong to the set {0, 1}) that is equal to 1 if eith…

http://codeforces.com/contest/1004/problem/D 题意: 在n×m的方格中,选定一个点(x,y)作为中心点,该点的值为0,其余点的值为点到中心点的曼哈顿距离. 现在给出t个点的值,问是否可以确定一个由t个点组成的方格,方格中的值由这t个点组成,如果有,则任一输出一个方格的规模n.m和中心点的坐标x.y. 思路: 参考了https://blog.csdn.net/FSAHFGSADHSAKNDAS/article/details/80951796的题解. #…

https://codeforces.com/contest/1080/problem/E 题意 有一个n*m(<=250)的字符矩阵,对于每个子矩阵的每一行可以任意交换字符的顺序,使得每一行每一列都是一个回文串,问最多有多少个这样的子矩阵 思路 首先可以思考如何暴力,枚举四个边界(子矩阵),然后判定一下子矩阵的每一行每一列,这样的复杂度是nmnmn*m 很明显需要找一下规律来优化一下复杂度, 对于每一行来说,最多只能存在一种字母的数量是奇数,这样一定可以保证这一行是回文串 对于每一列来说,因为…

地址 Problem - C - Codeforces 题意 每个格子,该格子和相邻的格子的值不能相同 题解 思维题, 先从1~n输出奇数,再输出偶数 代码 #include <iostream> #include <string> #include <algorithm> using namespace std; typedef long long LL; int a[110][110]; int main() { LL n, t; cin >> t; w…

B. OR in Matrix   Let's define logical OR as an operation on two logical values (i. e. values that belong to the set {0, 1}) that is equal to 1 if either or both of the logical values is set to 1, otherwise it is 0. We can define logical OR of three…

Codeforces Round #372 (Div. 2) 不知不觉自己怎么变的这么水了,几百年前做A.B的水平,现在依旧停留在A.B水平.甚至B题还不会做.难道是带着一种功利性的态度患得患失?总共才打的几场 CF 节节掉分.学了快一年了成了个水货. 废话就不多说了,来看这次的这两题吧.很多CF的题是不想写博客的,如果题目质量很好的话我倒是愿意留在我的博客里: A. Crazy Computer time limit per test 2 seconds memory limit per te…

 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 #346 (Div. 2)---E. New Reform E. New Reform time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Berland has n cities connected by m bidirectional roads. No road connects a city…

Pythagorean Triples 题目链接: http://codeforces.com/contest/707/problem/C Description Katya studies in a fifth grade. Recently her class studied right triangles and the Pythagorean theorem. It appeared, that there are triples of positive integers such th…

Codeforces Round #277 (Div. 2) A. Calculating Function time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output For a positive integer n let's define a function f: f(n) =  - 1 + 2 - 3 + .. + ( - 1)n…

Codeforces Round #549 (Div. 2) B. Nirvana [题目描述] B. Nirvana time limit per test1 second memory limit per test256 megabytes inputstandard input outputstandard output Kurt reaches nirvana when he finds the product of all the digits of some positive int…

Codeforces Codeforces Round #484 (Div. 2) E. Billiard 题目连接: http://codeforces.com/contest/982/problem/E Description Consider a billiard table of rectangular size $n \times m$ with four pockets. Let's introduce a coordinate system with the origin at t…

Codeforces Codeforces Round #484 (Div. 2) D. Shark 题目连接: http://codeforces.com/contest/982/problem/D Description For long time scientists study the behavior of sharks. Sharks, as many other species, alternate short movements in a certain location and…

Codeforces Round #275 (Div. 1)A. Diverse Permutation Time Limit: 1 Sec  Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/482/problem/A Description Permutation p is an ordered set of integers p1,   p2,   ...,   pn, consisting of n distinct posi…

Codeforces Round #297 (Div. 2)E. Anya and Cubes Time Limit: 2 Sec  Memory Limit: 512 MBSubmit: xxx  Solved: 2xx 题目连接 http://codeforces.com/contest/525/problem/E Description Anya loves to fold and stick. Today she decided to do just that. Anya has n c…

Codeforces Round #297 (Div. 2)C. Ilya and Sticks Time Limit: 2 Sec  Memory Limit: 256 MBSubmit: xxx  Solved: 2xx 题目连接 http://codeforces.com/contest/525/problem/C Description In the evening, after the contest Ilya was bored, and he really felt like ma…

Codeforces Round #297 (Div. 2)A. Vitaliy and Pie Time Limit: 2 Sec  Memory Limit: 256 MBSubmit: xxx  Solved: 2xx 题目连接 http://codeforces.com/contest/525/problem/A Description After a hard day Vitaly got very hungry and he wants to eat his favorite pot…

Codeforces Round #296 (Div. 1)C. Data Center Drama Time Limit: 2 Sec  Memory Limit: 256 MBSubmit: xxx  Solved: 2xx 题目连接 http://codeforces.com/contest/528/problem/C Description The project of a data center of a Big Software Company consists of n compu…

Codeforces Round #422 (Div. 2) Table of Contents Codeforces Round #422 (Div. 2)Problem A. I'm bored with lifeProblem B.Crossword solvingProblem C. Hacker, pack your bags! Problem A. I'm bored with life A. I'm bored with life Holidays have finished. T…

Codeforces Round #272 (Div. 2) A. Dreamoon and Stairs time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Dreamoon wants to climb up a stair of n steps. He can climb 1 or 2 steps at each move.…

Codeforces Round #603 (Div. 2) A. Sweet Problem A. Sweet Problem time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You have three piles of candies: red, green and blue candies: the first pile…

Codeforces Round #713 (Div. 3) Editorial 记录一下自己写的前二题本人比较菜 A. Spy Detected! You are given an array a consisting of n (n≥3) positive integers. It is known that in this array, all the numbers except one are the same (for example, in the array [4,11,4,4]…

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…