摘要： Collecting BugsTime Limit: 10000MSMemory Limit: 64000KTotal Submissions: 1244Accepted: 523Case Time Limit: 2000MSSpecial JudgeDescriptionIvan is fond of collecting. Unlike other people who collect post stamps, coins or other material stuff, he collects software bugs. When Ivan gets a new program, he 阅读全文

摘要： 概率DP主要用于求解期望、概率等题目。转移方程有时候比较灵活。一般求概率是正推，求期望是逆推。通过题目可以体会到这点。首先先推荐几篇参考的论文：《信息学竞赛中概率问题求解初探》《浅析竞赛中一类数学期望问题的解决方法》 《有关概率和期望问题的研究 》1、POJ 3744 Scout YYF I此题是一个用矩阵优化的求概率的题目。主要思想是分段，根据转移方程用矩阵求解。题解见 herePOJ 3744/*POJ 3744C++ 0ms 184K*/#include<stdio.h>#include<string.h>#include<algorithm>#inc 阅读全文

摘要： Scout YYF ITime Limit: 1000MSMemory Limit: 65536KTotal Submissions: 3723Accepted: 928DescriptionYYF is a couragous scout. Now he is on a dangerous mission which is to penetrate into the enemy's base. After overcoming a series difficulties, YYF is now at the start of enemy's famous "mine 阅读全文

摘要： 这几天学习了一下插头DP，刷了11道题。对插头DP有了点理解。插头DP就先告一段落吧！ 后面还有插头DP的广义路径和其它复杂应用，以后有机会再补上吧！ kuangbin首先入门推荐的还是cdq的论文：《基于连通性状态压缩的动态规划问题》http://wenku.baidu.com/view/4fe4ac659b6648d7c1c74633.html上面的论文关于插头和轮廓线等概念讲得很清楚。而且关于插头DP的精髓也讲得很透了。插头DP其实就是每格进行状态转移。看懂原理和写代码还是有段距离的，可以结合代码去加深理解原理。同时形成适合自己风格的代码模板。HDU 1693 Eat the Trees 阅读全文

摘要： circuitsTime Limit: 30000/15000 MS (Java/Others)Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 418Accepted Submission(s): 141Problem Description Given a map of N * M (2 <= N, M <= 12) , '.' means empty, '*' means walls. You need to build K circuits and no circuit 阅读全文

摘要： Beautiful MeadowTime Limit: 5 Seconds Memory Limit: 32768 KBTom's MeadowTom has a meadow in his garden. He divides it into N * M squares. Initially all the squares are covered with grass and there may be some squares cannot be mowed.(Let's call them forbidden squares.) He wants to mow down t 阅读全文