A string is binary, if it consists only of characters "0" and "1". String v is a substring of string w if it has a non-zero length and can be read starting from some position in string w. For example, string "010" has six sub…

A string is binary, if it consists only of characters "0" and "1". String v is a substring of string w if it has a non-zero length and can be read starting from some position in string w. For example, string "010" has six sub…

传送门:https://284914869.github.io/AEoj/560.html 题目简述: 定义"项"为两个不同变量相乘. 求一个由多个不同"项"相加,含有n个不同变量的式子的最大值. 另外限制了每一个变量的最大最小值R[i]和L[i]和所有变量之和的最大值Max. n<=13 题外话: 刚开始做这道题的时候,感觉意外眼熟? codeforces 839 E(此题的退化版):http://codeforces.com/contest/839/pro…

http://codeforces.com/contest/868/problem/D 优化:两个串合并 原有状态+ 第一个串的尾部&第二个串的头部的状态 串变为第一个串的头部&第二个串的尾部 注意: 头尾不能重复 如串A合并串A 这就意味着串的头尾不能有重合, 详见代码 #include <cstdio> #include <cstdlib> #include <cmath> #include <cstring> #include <…

http://codeforces.com/gym/101138/problem/A 感觉有一种套路就是总长度 <= 某一个数的这类题,大多可以分块 首先把集合串按长度分块,对于每一个询问串, 在 > magic的big集合里,因为最多sqrtn个,可以暴力枚举每一个,然后暴力枚举询问串的每一个长度是其的子串,判断是否相等 在 <= magic的small集合里,枚举每一个长度是magic, magic-1, magic-2, magic-3........1的字符串,然后看看是否在sm…

Problem for Nazar Nazar, a student of the scientific lyceum of the Kingdom of Kremland, is known for his outstanding mathematical abilities. Today a math teacher gave him a very difficult task. Consider two infinite sets of numbers. The first set con…

题目链接 时间复杂度 O(n*n*|s| ) 纯暴力,通过string.substr()函数来构造每一个字符串平移后的字符串. #include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #include <cmath> #include <queue> #include <stack> #include <map>…

题目链接 题意:英语很简单,自己取读吧. 思路: 既然n和i字符串的长度都很小,最大才50,那么就是只要能出答案就任意暴力瞎搞. 本人本着暴力瞎搞的初衷,写了又臭又长的200多行(代码框架占了50行).反正不忘初衷就对了. 暴力:枚举每一个字符串,然后暴力去算其他字符串变成该字符串需要用多少步骤,然后在众多答案中取最小值. 需要注意的是答案是-1的情况,需要用到字符串的最小表示法,预处理进行把所有的字符串变成最小表示法的字符串,如果有不一样的,那么就输出-1.因为可以通过首位对接搞成的字符串的最…

题意:一个等腰直角三角形一样的周期函数(只有x+轴),经过给定的点(a,b),并且半周期为X,使X尽量大,问X最大为多少? 如果a=b,结果就为b 如果a<b无解. 否则,b/(2*k*x-a)=1或者b/(a-2*k*x)=1;以前者为例,x=(a-b)/(2*k).x越小越好,那么k尽量大,但是K过大,x就会小于b,x小于b就无法穿过(a,b).k要大又不能过大就满足二分的要求,就能二分. 乱码: //#pragma comment(linker,"/STACK:1024000000,…

题意:定义了字符串的相等,问两串是否相等. 卡了时间,空间,不能新建字符串,否则会卡. #pragma comment(linker,"/STACK:1024000000,1024000000") #include<iostream> #include<cstdio> #include<string> #include<cstring> #include<vector> #include<cmath> #inclu…

大意: 给定两个串$s,t$, 每次操作任选长度$len$, 分别翻转$s,t$中一个长$len$的子串, 可以进行任意次操作, 求判断能否使$s$和$t$相同. 字符出现次数不一样显然无解, 否则若某种字符出现多次, 显然有解, 否则只要逆序对奇偶性相同就有解, 不同则无解. #include <iostream> #include <sstream> #include <algorithm> #include <cstdio> #include <…

大意: 给定字符串$s$, $p$, 对于$0\le x\le |s|$, 求$s$删除$x$个字符后, $p$在$s$中的最大出现次数. 显然答案是先递增后递减的, 那么问题就转化求最大出现次数为$y$时, 求$S$所需要删除的最少字符数. 先暴力O(n^2)求出以每个字符开头匹配完一个$p$后的最小右端点, 然后$dp$即可. #include <iostream> #include <sstream> #include <algorithm> #include &…

大意: 给定字符串$a$,$b$, $b$可以任选一段连续的区间删除, 要求最后$b$是$a$的子序列, 求最少删除区间长度. 删除一段连续区间, 那么剩余的一定是一段前缀和后缀. 判断是否是子序列可以用序列自动机, 最后双指针合并前缀与后缀的答案. #include <iostream> #include <sstream> #include <algorithm> #include <cstdio> #include <math.h> #in…

A positive integer aa is given. Baron Munchausen claims that he knows such a positive integer nn that if one multiplies nn by aa, the sum of its digits decreases aa times. In other words, S(an)=S(n)/aS(an)=S(n)/a, where S(x)S(x) denotes the sum of di…

Codeforces Round #112 (Div. 2) C. Another Problem on Strings 题意 给一个01字符串,求包含\(k\)个1的子串个数. 思路 统计字符1的位置,两端用0填充. \(k=0\)需要特判. 代码 C. Another Problem on Strings D. Beard Graph 题意 一棵\(N(N \le 10^5)\)个点的树,每条边被染成黑色或白色,初始都是黑色. \(M(M \le 3 \times 10^5)\)次操作,要么…

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. 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…

Codeforces 25E Test E. Test Sometimes it is hard to prepare tests for programming problems. Now Bob is preparing tests to new problem about strings - input data to his problem is one string. Bob has 3 wrong solutions to this problem. The first gives…

D. Spongebob and Squares Spongebob is already tired trying to reason his weird actions and calculations, so he simply asked you to find all pairs of n and m, such that there are exactly x distinct squares in the table consisting of n rows and m colum…

这场cf 做的很差,,第一题犯了一个很低级的错误..把i写成了J.... 第二题 想的太复杂了...其实我们只需要 考虑每个人自己的负债情况就行了,就是假设每个人把别人 欠他的钱,拿过来还给别人..这就是最简单的欠债关系了... 在做题的过程中也没有专心..做了以后就去干其他事了 最后就是一道题也没有过,rating已经掉的不行了.. 题目:http://codeforces.com/contest/376/problem/A http://codeforces.com/contest/376/…

Description Sometimes it is hard to prepare tests for programming problems. Now Bob is preparing tests to new problem about strings — input data to his problem is one string. Bob has 3 wrong solutions to this problem. The first gives the wrong answer…

B. Substrings Sort time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You are given nn strings. Each string consists of lowercase English letters. Rearrange (reorder) the given strings in such…

    A CodeForces 807A Is it rated?     B CodeForces 807B T-Shirt Hunt     C CodeForces 807C Success Rate     D CodeForces 807D Dynamic Problem Scoring     E CodeForces 807E Prairie Partition 点击题号进入题面 --------- 新笔记本终于到了,可以愉快的写代码了.. ------ A 807A 题意: 给…

时间相对来说还是比较合适的,正好放假就可以打一打啦. A. New Building for SIS:http://codeforces.com/contest/1020/problem/A 题意概述:有n座楼,每座楼有h层.上一层楼和下一层楼各需要一分钟,在a,b两层之间有跨楼的通道,每次可以走到相邻的楼,时间也是一分钟,给出k组询问,求每组点对之间的最小时间. 打CF学英语.一开始看起来像是最短路,但是画画图就发现并没有那么复杂,首先两栋楼之间的那一段是无论如何都要走的,关键是a,b的限制,…

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. A Good Contest 题目连接: http://www.codeforces.com/contest/681/problem/A Description Codeforces user' handle color depends on his rating - it is red if his rating is greater or equal to 2400; it is orange if his rating is less than 2400 but greater or…

B. Pen Pineapple Apple Pen Solved. 题意:将一个序列合并成一个数. 思路:分类讨论一下, 水. #include<bits/stdc++.h> using namespace std; ; char str[maxn]; bool solve() { ); ) return true; == ) len = len >> ; ) return false; len = strlen(str + ); ; i <= len; i += ) ]…

E. Test time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Sometimes it is hard to prepare tests for programming problems. Now Bob is preparing tests to new problem about strings — input data…

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…

E. Test time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Sometimes it is hard to prepare tests for programming problems. Now Bob is preparing tests to new problem about strings — input data…