Interesting Vertices(前向星+思维+dfs回溯) 参考博客:https://blog.csdn.net/I_believe_CWJ/article/details/102472012 题目大意:给你一课有n个节点的树,其中有k个节点被染色,求有多少个节点满足自身没有被染色并且它的每棵子树中都至少有一个节点被染色.解题思路:dfs回溯类似求树的重心的方式求解,dfsdfs回溯可以得到每个节点的它的子树中是否都有染色的点并统计所有子树中染色点的个数sum,然后走向父亲的那棵子树中…

E. Cactus   A connected undirected graph is called a vertex cactus, if each vertex of this graph belongs to at most one simple cycle. A simple cycle in a undirected graph is a sequence of distinct vertices v1, v2, ..., vt (t > 2), such that for any i…

8. 过滤噪声边 在当前的伴生关系中,边的权重是基于一对概念同时出现在一篇论文中的频率来计算的.这种简单的权重机制的问题在于:它并没有对一对概念同时出现的原因加以区分,有时一对概念同时出现是由于它们具有某种值得我们关注的语义关系,但有时一对概念同时出现只是因为都频繁地出现在所有文档中,同时出现只是碰巧而已.我们需要使用一种新的权重机制,在给定概念在数据中的总体频繁度的情况下,它需要考虑给定的两个概念对于一个文档的“意义”或是“新颖度”.我们将使用皮尔逊卡方测试(Pearson’s chi-squ…

E. Interesting Graph and Apples 题目连接: http://www.codeforces.com/contest/9/problem/E Description Hexadecimal likes drawing. She has drawn many graphs already, both directed and not. Recently she has started to work on a still-life «interesting graph a…

This paper presented a very interesting topic. Censorship in China has always drawn people's attention since in a perspective of universal values censorship repress the free will of people to express themselves. This paper, focusing on the censorship…

题目描述 Recently, Miss Huang want to receive a Tree as her birthday gift! (What a interesting person!)  As a interesting person, Miss Huang likes interesting tree. The interesting tree is a tree with the Max interesting degree. The interesting degree eq…

题目 Source http://acm.hdu.edu.cn/showproblem.php?pid=5785 Description Alice get a string S. She thinks palindrome string is interesting. Now she wanna know how many three tuple (i,j,k) satisfy 1≤i≤j<k≤length(S), S[i..j] and S[j+1..k] are all palindrom…

2070. Interesting Numbers Time limit: 2.0 secondMemory limit: 64 MB Nikolay and Asya investigate integers together in their spare time. Nikolay thinks an integer is interesting if it is a prime number. However, Asya thinks an integer is interesting i…

H - Solve this interesting problem Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u Submit Status Practice HDU 5323 Appoint description:  System Crawler  (2015-07-28) Description Have you learned something about segment tr…

Interesting Fibonacci Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 665    Accepted Submission(s): 114 Problem Description In mathematics, the Fibonacci numbers are a sequence of numbers named…