题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5938 题意:给出一个长度最大是2020的数字串, 你要把数字串划分成55段, 依次填入'+', '-', '*', '/', 问能得到的最大结果. 想让这个结果最大,那尽可能让减号左边的数最大,只需要关心左边的第一位是一个数还是最后一位是一个数,后面的枚举*和/的位置就行了. #include <bits/stdc++.h> using namespace std; typedef long lo…

1065: Operations on Grids Time Limit: 3 Sec  Memory Limit: 128 MB Submit: 17  Solved: 4 [Submit][Status][Web Board] Description 你有一个  9  位数字串,现在你把这个数字的每一位填到  3 × 3  格子上.如果数 字是  123456789,那么填到  3 × 3  格子上会得到:  123 456 789 现在你可以对这  3 × 3  格子做四种操作: 现在给你…

15年出现的JAVA反序列化漏洞,另一个是redis配置不当导致机器入侵.只要redis是用root启动的并且未授权的话,就可以通过set方式直接写入一个authorized_keys到系统的/root/.ssh/目录下实现免密码登陆他人的Linux服务器.从而达到入侵成功的效果.fail2ban是一款很棒的开源服务软件,可以监视你的系统日志,然后匹配日志的错误信息(正则式匹配)执行相应的屏蔽动作(一般情况下是防火墙),而且可以发送e-mail通知系统管理员,很好.很实用.很强大!简单来说其功能…

Shuffle'm Up Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 10003   Accepted: 4631 Description A common pastime for poker players at a poker table is to shuffle stacks of chips. Shuffling chips is performed by starting with two stacks o…

传送门 Description You are given a table consisting of n rows and m columns. Numbers in each row form a permutation of integers from 1 to m. You are allowed to pick two elements in one row and swap them, but no more than once for each row. Also, no more…

Problem Description In mathematics and computer science, an algorithm describes a set of procedures or instructions that define a procedure. The term has become increasing popular since the advent of cheap and reliable computers. Many companies now e…

http://acm.hdu.edu.cn/showproblem.php?pid=5475 An easy problem Time Limit: 8000/5000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 755 Accepted Submission(s): 431 Problem Description One day, a useless calculator was…

C. Amr and Chemistry Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/558/problem/C Description Amr loves Chemistry, and specially doing experiments. He is preparing for a new interesting experiment. Amr has n different type…

描述 In the traditional RMQ (Range Minimum Query) problem, we have a static array A. Then for each query (L, R) (L<=R), we report the minimum value among A[L], A[L+1], …, A[R]. Note that the indices start from 1, i.e. the left-most element is A[1]. In…

Problem DescriptionIn a galaxy far, far away, there are two integer sequence a and b of length n.b is a static permutation of 1 to n. Initially a is filled with zeroes.There are two kind of operations:1. add l r: add one for al,al+1...ar2. query l r:…