对于前30%的数据,可以考虑dp,f[i][j][k]表示时间为i,在i,j位置的方案数,枚举转移即可.要注意的是可以走到矩阵外. 对于另外30%数据,考虑推一下式子,设向右走y步,左z,上s,下x.那么y-z=n,s-x=m.所以我们枚举s就可以求得sxzy,步数确定之后就比较简单了,显然答案为 $∑C_T^s*C_{T-s}^x*C_{T-s-x}^z*C_{T-s-x-z}^y$,化减得ans=∑$\frac{T!}{s!x!z!y!}$,由于mod是质数,直接逆元干就行了. 对于100%…

考试T2,考试时打了个$O(n^3)$dp暴力,思路还是很好想的,但细节也不少,然后滚动数组没清空,而且题又看错了,只得了10pts,真是血的教训. 题解: 其实看数据范围,给出了模数是否为质数,其实应该能推测出这是道数学题(但是不会推式子啊) 我们仔细分析一下问题,我们设$ri,le,up ,down$分别为向右左上下走的步数,且总步数为T,然后我们只要知道,向一个方向走的步数就能得到其他的,但是我们发现光凭一个是求不出的,我们再转化一下思路,我们设在上下方向走的步数为$k$,则$up+dow…

Park Visit Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1826    Accepted Submission(s): 798 Problem Description Claire and her little friend, ykwd, are travelling in Shevchenko's Park! The pa…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4607 题目大意:给你n个点,n-1条边,将图连成一棵生成树,问你从任意点为起点,走k(k<=n)个点,至少需要走多少距离(每条边的距离是1): 思路:树形dp求树的直径r: a:若k<=r+1 ,ans = k-1: b:若k>=r+1,ans = r+(k-(r+1))*2: 代码: #include "stdio.h" #include "string.h&…

A website domain like "discuss.leetcode.com" consists of various subdomains. At the top level, we have "com", at the next level, we have "leetcode.com", and at the lowest level, "discuss.leetcode.com". When we visit…

A website domain like "discuss.leetcode.com" consists of various subdomains. At the top level, we have "com", at the next level, we have "leetcode.com", and at the lowest level, "discuss.leetcode.com". When we visit…

题目要求 A website domain like "discuss.leetcode.com" consists of various subdomains. At the top level, we have "com", at the next level, we have "leetcode.com", and at the lowest level, "discuss.leetcode.com". When we…

Problem A. Alien Visit 题目连接: http://codeforces.com/gym/100714 Description Witness: "First, I saw only one UFO. It was shining with cold-blue light. Closer to the center of the object, the light was pink. It hung over the field, then began to blink an…

Park Visit Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 523    Accepted Submission(s): 236 Problem Description Claire and her little friend, ykwd, are travelling in Shevchenko's Park! The par…

A website domain like "discuss.leetcode.com" consists of various subdomains. At the top level, we have "com", at the next level, we have "leetcode.com", and at the lowest level, "discuss.leetcode.com". When we visit…

严重: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListenerorg.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in Serv…

A website domain like "discuss.leetcode.com" consists of various subdomains. At the top level, we have "com", at the next level, we have "leetcode.com", and at the lowest level, "discuss.leetcode.com". When we visit…

执行mapreduce报错java.lang.Exception: java.lang.RuntimeException: java.lang.NoSuchMethodException: com.web.visit.main.ClickVist$VisitMapper.<init>(), 原因是map类和reduce没有加static修饰,因为hadoop在调用map和reduce类时采用的反射调用,内部类不是静态的,没有获取到内部类的实例 解决方法 1.在内部类加上static修饰 2.将…

异常完整信息 严重: Servlet.service() for servlet RegServlet threw exception java.lang.NoSuchMethodError: org.objectweb.asm.ClassVisitor.visit(IILjava/lang/String;Ljava/lang/String;[Ljava/lang/String;Ljava/lang/String;)V at net.sf.cglib.core.ClassEmitter.begi…

A website domain like "discuss.leetcode.com" consists of various subdomains. At the top level, we have "com", at the next level, we have "leetcode.com", and at the lowest level, "discuss.leetcode.com". When we visit…

在进行Rspec 编译测试: bundle exec rspec spec/requests/static_pages_spec.rb 提示错误: FF Failures: 1) Static pages Home page should have the content 'Sample App' Failure/Error: visit '/static_pages/home' NoMethodError: undefined method `visit' for #<RSpec::Core:…

传送门 Park Visit Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 3721    Accepted Submission(s): 1667 Problem Description Claire and her little friend, ykwd, are travelling in Shevchenko's Park! T…

Problem Description Claire and her little friend, ykwd, are travelling in Shevchenko's Park! The park is beautiful - but large, indeed. N feature spots in the park are connected by exactly (N-1) undirected paths, and Claire is too tired to visit all…

HDU#4607. Park Visit 题目描述 Claire and her little friend, ykwd, are travelling in Shevchenko's Park! The park is beautiful - but large, indeed. N feature spots in the park are connected by exactly (N-1) undirected paths, and Claire is too tired to visi…

之前两篇都是介绍与Value相关的,这篇我继续这个话题吧,正好凑个"Value三板斧系列...".在非常久非常久曾经.我用写过一篇博客,关于怎样查看CCArray与CCDictionary里存放的元素:http://blog.csdn.net/star530/article/details/23877429如今既然它俩已经都是过去式了,那么之前的查看方法肯定也是不能用了. 而Value作为它们的替代者之中的一个.自然也有它查看元素的方法.那就是getDescription()这个接口,…

在使用CGLIB进行动态代理的时候,报了[java.lang.VerifyError: class net.sf.cglib.core.DebuggingClassWriter overrides final method visit. (IILjava/lang/String;Ljava/lang/String;Ljava/lang/String;[Ljava/lang/String;)V]错误. 报错的原因 原因是因为我做的是SpringBoot的项目,在SpringBoot的架构中已经存在…

problem 811. Subdomain Visit Count solution: class Solution { public: vector<string> subdomainVisits(vector<string>& cpdomains) { vector<string> res; unordered_map<string, int> subdomain; ; for(auto cpdomain:cpdomains) { spaceI…

问题 该文章的最新版本已迁移至个人博客[比特飞],单击链接 https://www.byteflying.com/archives/3814 访问. 一个网站域名,如"discuss.leetcode.com",包含了多个子域名.作为顶级域名,常用的有"com",下一级则有"leetcode.com",最低的一级为"discuss.leetcode.com".当我们访问域名"discuss.leetcode.com&…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 字典统计次数 日期 题目地址:https://leetcode.com/problems/subdomain-visit-count/description/ 题目描述 A website domain like "discuss.leetcode.com" consists of various subdomains. At the to…

Question 811. Subdomain Visit Count Example 1: Input: ["9001 discuss.leetcode.com"] Output: ["9001 discuss.leetcode.com", "9001 leetcode.com", "9001 com"] Explanation: We only have one website domain: "discuss.…

http://acm.hdu.edu.cn/showproblem.php?pid=4607 先求树的直径 方法:两遍bfs ,任选一点 a  求到a点最远的一点b ,然后 求到b点最远点 c 这样 b和c之间的路径为 树的直径 然后讨论 假设直径上的点个数为 k   要访问的点个数为 v 1)如果v<=k 则可以直接在直径上参观  路径为 v-1 2)如果v>k 首先还是要走直径 但是 m=v-k  这m个点要到其他枝叶上访问 一共要花费 2*m 代码: #include<iostre…

两次DFS求树直径方法见 这里. 这里的直径是指最长链包含的节点个数,而上一题是指最长链的路径权值之和,注意区分. K <= R: ans = K − 1; K > R:   ans = R − 1 + ( K − R ) ∗ 2; #include <cstdio> #include <cstring> #include <cstdlib> #include <algorithm> using namespace std; ; struct n…

求树上最长链:两遍搜索. 第一次从树上任意点开始,最远点必然是某一条最长链上的端点u. 第二次从u开始,最远点即该最长链的另一端点. 先在最长链上走,不足再去走支链. 把询问数m错打成n,狠狠wa了一次= = #include<stdio.h> #include<string.h> ; struct E{ int v,next; }e[MAXN<<]; struct Q{ int p,c; }q[MAXN]; int tol; int head[MAXN]; int v…

[题目]题意:N个城市形成一棵树,相邻城市之间的距离是1,问访问K个城市的最短路程是多少,共有M次询问(1 <= N, M <= 100000, 1 <= K <= N). [思路] 访问K个城市的路线: 可以发现它由一条主线和若干支线构成,并且主线上的边只用访问一次,而支线上的边必须且只用访问两次.而题目给定的是一棵树,那么访问K的城市就必须且仅需要走K-1条边.总边数是固定的,我们只需要保证主线最长即可,所以就是在树中找最长链. [找最长链]树形dp,dp[i]表示他的子树的最…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4607 首先考虑找一条最长链长度k,如果m<=k+1,那么答案就是m.如果m>k+1,那么最长链上还有其他分支,来回走一遍,因此答案为2*m-k-1...求最长链可以DP,两次BFS或者DFS等.. //STATUS:C++_AC_453MS_3524KB #include <functional> #include <algorithm> #include <iost…