题目链接:Codeforces 459E Pashmak and Graph 题目大意:给定一张有向图,每条边有它的权值,要求选定一条路线,保证所经过的边权值严格递增,输出最长路径. 解题思路:将边依照权值排序,每次将同样权值的边同一时候增加,维护每一个点作为终止点的最大长度就可以. #include <cstdio> #include <cstring> #include <algorithm> using namespace std; const int maxn…

Discription In this problem you have to build tournament graph, consisting of n vertices, such, that for any oriented pair of vertices (v, u) (v ≠ u) there exists a path from vertexv to vertex u consisting of no more then two edges. A directed graph…

CodeForces 295B Greg and Graph 题解 \(Floyd\) 算法是一种基于动态规划的算法,以此题为例介绍最短路算法中的 \(Floyd\) 算法. 我们考虑给定一个图,要找出 \(i\) 号点到 \(j\) 号点的最短路径.则该最短路径只有两种可能: \(i\) 号点直接到达 \(j\) 号点的路径中产生最短路径 \(i\) 号点经过一些中间点到达 \(j\) 号点的路径中产生最短路径 我们添加一个点 \(k\),使得 \(i\) 号点到 \(j\) 号点再添加后产生…

传送门:https://codeforces.com/gym/100801 题意: 给你一个DAG图,你最多可以进行k次操作,每次操作可以连一条有向边,问你经过连边操作后最小拓扑序的最大值是多少 题解: 最小拓扑序:与普通拓扑序不同的是,用一个小根堆记录入度为0的点做拓扑排序即可 怎么样使得最小拓扑序最大呢?已知拓扑序是入度小的点在前面,那么,如果我们可以使得大的点的度数尽量小或者是小的点度数尽量大就可以使得拓扑序变大了,由于我们只有加边的操作,那么我们可以将边尽量从大的点往小的点去连边 我们定…

Description You are given undirected weighted graph. Find the length of the shortest cycle which starts from the vertex 1 and passes throught all the edges at least once. Graph may contain multiply edges between a pair of vertices and loops (edges fr…

http://www.codeforces.com/problemset/problem/459/E 题意: 给出n个点,m条边的有向图,每个边有边权,求一条最长的边权上升的路径的长度. 思路:用f存边,g存点,然后排序转移,注意相同的要延迟转移 #include<cstdio> #include<cmath> #include<algorithm> #include<cstring> #include<iostream> struct edge…

并查集.... E. Information Graph time limit per test 1 second memory limit per test 512 megabytes input standard input output standard output There are n employees working in company "X" (let's number them from 1 to n for convenience). Initially the…

转载请注明出处: http://www.cnblogs.com/fraud/          ——by fraud  Bubble Sort Graph Iahub recently has learned Bubble Sort, an algorithm that is used to sort a permutation with n elements a1, a2, ..., an in ascending order. He is bored of this so simple al…

Greg and Graph time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output Greg has a weighed directed graph, consisting of n vertices. In this graph any pair of distinct vertices has an edge between…

题意: 让你选一些边,选边的前提是端点都被选了,求所有的边集中,边权和-点权和最大的一个. 题解: 对于每个边建一个点,然后就是裸的最大权闭合子图, 结果比赛的时候我的板子太丑,一直T,(不会当前弧优化...) 当时补题用的是蔡队的Dinic当前弧优化板子 今天重写了一遍 #include <bits/stdc++.h> #define endl '\n' #define ll long long #define all(x) x.begin(),x.end() #define IO ios:…