C. Trails and Glades time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output Vasya went for a walk in the park. The park has n glades, numbered from 1 to n. There are m trails between the glades.…

题目链接 \(Description\) 给定一张\(n\)个点\(m\)条边的无向图,允许有自环重边.求最少加多少条边后,其存在从\(1\)出发最后回到\(1\)的欧拉回路. 注意,欧拉回路是指要经过所有边,无边(边包括自环)连向的孤立点不需要考虑.但是\(1\)一定要经过. \(n,m\leq10^6\). \(Solution\) 如果图连通,奇度数点两两连边即可. 如果图不连通,对于每个奇度数点需要向外连一条边:没有奇度数点的连通块就随便找一个点往外连两条边.另外强制选\(1\)即可.…

Vasya went for a walk in the park. The park has n glades, numbered from 1 to n. There are m trails between the glades. The trails are numbered from 1 to m, where the i-th trail connects glades xi and yi. The numbers of the connected glades may be the…

题目链接 题意 有一个\(n\)个点\(m\)条边的无向图(可能有重边和自环)(不一定联通).问最少添加多少条边,使得可以从\(1\)号点出发,沿着每条边走一遍之后回到\(1\)号点. 思路 其实就是加最少的边构成欧拉回路.对于度数为奇数的点,与其他度数为奇数的点相连即可. 如果一个联通块中点的度数全部为偶数,那么就需要与其他联通块连\(2\)条边.否则需要连一条. 如果一个点是孤立点,如果没有自环的话就不用管他.如果有自环就要与其他联通块相连. \(1\)号点即使是孤立点并且没有自环,也要与其…

题意 最少添加多少条边,使无向图有欧拉回路. n,m≤106 题解 求出每个点的度数 奇度数点需要连一条新边 仅有偶度数点的连通块需要连两条新边 答案为上面统计的新边数 / 2 注意:此题默认以1为起点,有重边自环. #include<iostream> #include<cstdio> #include<algorithm> #include<cmath> #include<string> using namespace std; ; int…

codeforces 459E E. Pashmak and Graph time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Pashmak's homework is a problem about graphs. Although he always tries to do his homework completely, he…

上一次我们拿学校的URP做了个小小的demo.... 其实我们还可以把每个学生的证件照爬下来做成一个证件照校花校草评比 另外也可以写一个物理实验自动选课... 但是出于多种原因,,还是绕开这些敏感话题.. 今天,我们来扒一下cf的题面! PS:本代码不是我原创 1. 必要的分析 1.1 页面的获取 一般情况CF的每一个 contest 是这样的: 对应的URL是:http://codeforces.com/contest/xxx 还有一个Complete problemset页面,它是这样的:…

http://codeforces.com/contest/738/problem/D Galya is playing one-dimensional Sea Battle on a 1 × n grid. In this game a ships are placed on the grid. Each of the ships consists of bconsecutive cells. No cell can be part of two ships, however, the shi…

http://codeforces.com/contest/738/problem/C Vasya is currently at a car rental service, and he wants to reach cinema. The film he has bought a ticket for starts in t minutes. There is a straight road of length s from the service to the cinema. Let's…

http://codeforces.com/contest/738/problem/A Polycarp has interviewed Oleg and has written the interview down without punctuation marks and spaces to save time. Thus, the interview is now a string s consisting of n lowercase English letters. There is…