一个萌新的成长之路 Background 同学们都回家了,只有我和wjh还有邢神在机房敲代码,吃random口味的方便面-- Description Translated by @PC_DOS from luogu In the popular spreadsheets systems (for example, in Excel) the following numeration of columns is used. The first column has number A, the se

题目链接:http://codeforces.com/problemset/problem/723/B 题目大意: 输入n,给出n个字符的字符串,字符串由 英文字母(大小写都包括). 下划线'_' .括号'(' ')' 组成.[括号不会嵌套] 求括号外面的连续字符串最大的字符串长度和括号内的连续字符串的个数. 举例: input 37_Hello_Vasya(and_Petya)__bye_(and_OK) output 5 4 括号外面的连续的字符串最长的字符串长度为 5 括号内有 4 个连续

题目链接: http://acm.hust.edu.cn/vjudge/problem/viewProblem.action?id=28214 题目大意:源串有如下变形:每次将串切为两半,位置颠倒形成新串.问经过K次变形后,与目标串相同的变形方案数.mod 1000000007. 解题思路: 奇葩的字符串DP.照着别人的题解写的,解释不出原理是什么. 首先统计出经过1次变形,就能和目标串相同的中间产物串(包含源串)的个数cnt.len表示源串长度,那么len-cnt就表示和目标串不同的个数. 用

B. Ohana Cleans Up Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/554/problem/B Description Ohana Matsumae is trying to clean a room, which is divided up into an n by n grid of squares. Each square is initially either clea

A. Kyoya and Photobooks Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/554/problem/A Description Kyoya Ootori is selling photobooks of the Ouran High School Host Club. He has 26 photos, labeled "a" to "z", a

A. Mike and palindrome time limit per test:2 seconds memory limit per test:256 megabytes input:standard input output:standard output Mike has a string s consisting of only lowercase English letters. He wants to change exactly one character from the s

A. Cutting Banner time limit per test:2 seconds memory limit per test:256 megabytes input:standard input output:standard output A large banner with word CODEFORCES was ordered for the 1000-th onsite round of Codeforcesω that takes place on the Miami

A. Saitama Destroys Hotel time limit per test:1 second memory limit per test:256 megabytes input:standard input output:standard output Saitama accidentally destroyed a hotel again. To repay the hotel company, Genos has volunteered to operate an eleva

题目链接:http://codeforces.com/problemset/problem/589/A 题目大意:给定n个邮件地址,任何电子邮件地址都将显示为“login @ domain”,其中: 1.a“login”是一个由非空的小写和大写字母序列以及点('.')和加号('+')组成的序列,从字母开始;2.a“domain”是一个由非空的小写和大写字母和点组成的序列,因为点将序列分成非空单词,仅由字母组成(即“domain”从字母开始,以字母结尾,不包含两个或多个连续点). 比较邮件地址时,

原文链接http://www.cnblogs.com/zhouzhendong/p/9010851.html 题目传送门 - Codeforces 316G3 题意 给定一个母串$s$,问母串$s$有多少本质不同的子串$t$是“好”的. 一个字符串$t$是好的,仅当$t$满足了所有的$n$个条件. 第$i$个条件用一个三元组$(p_i,L_i,R_i)$来描述. 其中$p_i$为一个字符串,$L_i,R_i$为整数,且$L_i\leq R_i$. 仅当字符串$t$在$p_i$中出现次数在$L_i

题目链接:https://codeforces.com/contest/1090/problem/B Examplesstandard input The most famous characters of Pushkin’s works are Onegin \cite{onegin}, Dubrovsky \cite{dubrovsky} and Tsar Saltan \cite{saltan}. \begin{thebibliography}{99} \bibitem{saltan} A

题目链接:https://codeforces.com/problemset/problem/1056/E One of Arkady's friends works at a huge radio telescope. A few decades ago the telescope has sent a signal $s$ towards a faraway galaxy. Recently they've received a response $t$ which they believe

https://codeforces.com/contest/1131/problem/D 题意 给你n个字符串,字符串长度总和加起来不会超过1e5,定义字符串相乘为\(s*s1=s1+s[0]+s1+s[1]+s1+...+s1+s[size-1]+s1+s[size]+s1\),求n个字符串依次相乘后最长连续字符相同的子序列长度 题解 鬼畜的题意 or 难以优化的复杂度,都需要观察性质才能做,第二串要插入第一个串每个字符之间,可以看出字符数增长的速度很快,所以并不能把整个字符存下来 只看一种

https://codeforces.com/contest/1121/problem/F 题意 给你一个有n(<=5000)个字符的串,有两种压缩字符的方法: 1. 压缩单一字符,代价为a 2. 压缩一个串,条件是这个串是前面整个串的连续子串,代价为b 题解 n<=5000 定义dp[i]为压缩前i个字符的代价,则答案为dp[n] dp[i]=min(dp[i-1]+a,min(dp[j]+b)(即[j+1,i]为[1,j]的子串)) 用字符串哈希处理判定一个串是否为前面的子串 坑点 串ab

https://codeforces.com/contest/1080/problem/E 题意 有一个n*m(<=250)的字符矩阵,对于每个子矩阵的每一行可以任意交换字符的顺序,使得每一行每一列都是一个回文串,问最多有多少个这样的子矩阵 思路 首先可以思考如何暴力,枚举四个边界(子矩阵),然后判定一下子矩阵的每一行每一列,这样的复杂度是nmnmn*m 很明显需要找一下规律来优化一下复杂度, 对于每一行来说,最多只能存在一种字母的数量是奇数,这样一定可以保证这一行是回文串 对于每一列来说,因为

题目链接:http://codeforces.com/contest/832/problem/B B. Petya and Exam time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output It's hard times now. Today Petya needs to score 100 points on Informatics

题目链接:http://codeforces.com/problemset/problem/219/C 题目大意: 给出一个字符串,只包含k种字符,问最少修改多少个字符(不增长新的种类)能够得到一个新的字符串,这个字符串满足相邻的字符没有相同的.解题思路:k=2时:字符串只能是ABABAB.....或者BABABA.....两种都枚举一下即可.k>2时:若有奇数个相同,如AAAAA则可变为ABABA的形式即可.若有偶数个相同,如AAAAAA则变为ABABAC的形式即可,C保证与后一个不同. 代码

题目链接:http://codeforces.com/problemset/problem/883/H Time limit: 3000 ms Memory limit: 262144 kB Kolya has a string s of length n consisting of lowercase and uppercase Latin letters and digits. He wants to rearrange the symbols in s and cut it into th

题目链接:http://codeforces.com/problemset/problem/208/A 题意 给出一个字符串,将字符串中的WUB给删去,如果两个字母间有WUB,则这两个字母用空格隔开 AC代码 #include <stdio.h> #include <string.h> #include <iostream> #include <algorithm> #include <math.h> #include <limits.h&

/** 题目:F. String Compression 链接:http://codeforces.com/problemset/problem/825/F 题意:压缩字符串后求最小长度. 思路: dp[i]表示前i个字符需要的最小次数. dp[i] = min(dp[j]+w(j+1,i)); (0<=j<i); [j+1,i]如果存在循环节(自身不算),那么取最小的循环节x.w = digit((i-j)/x)+x; 否则w = i-j+1; 求一个区间最小循环节: 证明:http://w

  A. Cutting Banner   time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output A large banner with word CODEFORCES was ordered for the 1000-th onsite round of Codeforcesω that takes place on the Mi