题目传送门 /* 二分图点染色:这题就是将点分成两个集合就可以了,点染色用dfs做, 剩下的点放到点少的集合里去 官方解答:首先二分图可以分成两类点X和Y, 完全二分图的边数就是|X|*|Y|.我们的目的是max{|X|*|Y|}, 并且|X|+|Y|=n. 修正:实现多连通块染色,然后贪心选择,将两个集合个数差大的连通块优先添加,能尽量使得un*vn最大 */ #include <cstdio> #include <algorithm> #include <cstring&…

题目地址:http://bestcoder.hdu.edu.cn/contests/contest_showproblem.php?cid=610&pid=1004 问题描述 Soda有一个$n$个点$m$条边的二分图, 他想要通过加边使得这张图变成一个边数最多的完全二分图. 于是他想要知道他最多能够新加多少条边. 注意重边是不允许的. 输入描述 输入有多组数据. 第一行有一个整数$T$ $(1 \le T \le 100)$, 表示测试数据组数. 然后对于每组数据: 第一行报包含两个整数$n$…

Souvenir  Accepts: 1078  Submissions: 2366  Time Limit: 2000/1000 MS (Java/Others)  Memory Limit: 262144/262144 K (Java/Others) Problem Description Today is the 1st anniversary of BestCoder. Soda, the contest manager, wants to buy a souvenir for each…

Problem Description Soda has a bipartite graph with n vertices and m undirected edges. Now he wants to make the graph become a complete bipartite graph with most edges by adding some extra edges. Soda needs you to tell him the maximum number of edges…

Problem Description Soda has a bipartite graph with n vertices and m undirected edges. Now he wants to make the graph become a complete bipartite graph with most edges by adding some extra edges. Soda needs you to tell him the maximum number of edges…

题目传送门 /* 官方题解: 这个题看上去是一个贪心, 但是这个贪心显然是错的. 事实上这道题目很简单, 先判断1个是否可以, 然后判断2个是否可以. 之后找到最小的k(k>2), 使得(m-k)mod6=0即可. 证明如下: 3n(n-1)+1=6(n*(n-1)/2)+1, 注意到n*(n-1)/2是三角形数, 任意一个自然数最多只需要3个三角形数即可表示. 枚举需要k个, 那么显然m=6(k个三角形数的和)+k, 由于k≥3, 只要m?k是6的倍数就一定是有解的. 事实上, 打个表应该也能…

http://acm.hdu.edu.cn/showproblem.php?pid=5311 Hidden String Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)Total Submission(s): 1499    Accepted Submission(s): 534 Problem Description Today is the 1st anniversar…

Today, Soda has learned a sequence whose n-th (n≥1) item is 3n(n−1)+1. Now he wants to know if an integer m can be represented as the sum of some items of that sequence. If possible, what are the minimum items needed? For example, 22=19+1+1+1=7+7+7+1…

Bipartite Graph Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 840    Accepted Submission(s): 285 Problem Description Soda has a bipartite graph with n vertices and m undirected edges. Now he w…

[HDU5807] [BestCoder Round #86 1004] Keep In Touch (DP) 题面 有三个人从一张N个点无重边的有向无环图上的三个点出发,每单位时间,他们分别选择当前点的一条出边走下去.有向无环图点有点权,任意时刻他们所在的三个点两两点权相差不超过K.他们可以在任意三个点同时结束.求合法的路径总数.N≤50. 分析 暴力的做法,设\(dp[i][j][k]\)表示第一个人在i,第二个人在j,第三个人在k的方案数,然后枚举三个人接着到的地方x,y,z,倒推\(dp…