Polycarp and Div 3 time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output Polycarp likes numbers that are divisible by 3. He has a huge number ss. Polycarp wants to cut from it the maximum number…

今天佛了,魔鬼周一,在线教学,有点小累,但还好,今天AC了一道,每日一道,还好达成目标,还以为今天完不成了,最近任务越来越多,如何高效完成该好好思考一下了~最重要的还是学业的复习和预习. 今日兴趣新闻: <流浪地球>中的逃生气囊球和马斯克有什么关系? 链接:https://mbd.baidu.com/newspage/data/landingsuper?context=%7B%22nid%22%3A%22news_8599496962815210358%22%7D&n_type=0&a…

http://codeforces.com/problemset/problem/1005/D  题意: 给一个仅包含数字的字符串,将字符串分割成多个片段(无前导0),求这些片段里最多有多少是3的倍数 思路一(贪心): from:https://blog.csdn.net/islittlehappy/article/details/81006849 一个数是3的倍数,则各位的和能被3整除. 对于单独的一个数字,如果是3的倍数,则ans++ 否则,考虑连续的两个数字,如果是,则ans++ 如果第三…

A. Div. 64 time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Top-model Izabella participates in the competition. She wants to impress judges and show her mathematical skills. Her problem is f…

C. Nice Garland time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You have a garland consisting of nn lamps. Each lamp is colored red, green or blue. The color of the ii-th lamp is sisi ('R',…

Alyona and Spreadsheet 这就是一道思维的题,谈不上算法什么的,但我当时就是不会,直到别人告诉了我,我才懂了的.唉 为什么总是这么弱呢? [题目链接]Alyona and Spreadsheet &题意: 给一n*m的表,之后给T个询问,每个询问是r1和r2,问从r1行到r2行(包括这2行)是否至少有一列是非递减的? &题解: 可以把给的n*m表处理一下,处理成b[i][j]数组,存的是第j列递增开始的位置是第几行. 这样,只有b中第r2行最小的小于r1就行了,否则就是…

Polycarp has nn coins, the value of the ii-th coin is aiai. Polycarp wants to distribute all the coins between his pockets, but he cannot put two coins with the same value into the same pocket. For example, if Polycarp has got six coins represented a…

E. Superhero Battle time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output A superhero fights with a monster. The battle consists of rounds, each of which lasts exactly nn minutes. After a round…

题目链接:http://codeforces.com/problemset/problem/1005/D 题意 给出个字符串(全是数字),把这个字符串换分成一些子串,最多能划分多少个能够被3整除的子串(字符串去掉前导零,0能被3整除) AC代码 #include <stdio.h> #include <string.h> #include <iostream> #include <algorithm> #include <math.h> #inc…

思路1: https://blog.csdn.net/qq_41730082/article/details/80984316 题目的意思是给你一串数字长度为(1-2e5),当然由于它的这一串数字是不打空格的输入,所以我用了string 定义了个字符串然后仅需要对字符串操作即可.题目要求得到的是:给你一串数组,你要找的是这串数组上能有多少段能被3整除的数,譬如3121,可以分成「3」.「1.2」.「1」,但最后的时候由于1不是3的倍数,所以ans=2:再举个有0的例子,100000可以分成「1」…

题目传送门 https://codeforces.com/contest/1103/problem/C 题解 这个题还算一个有难度的不错的题目吧. 题目给出了两种回答方式: 找出一条长度 \(\geq \frac nk\) 的路径: 找出 \(k\) 个简单环,满足长度不是 \(3\) 的倍数,并且每个环至少存在一个点不在别的环中. 很显然题目并不是要你随便挑一种回答方式开始单独研究.最有可能的情况是两种回答方式可以替补. 如果我们随便作出原图的一棵生成树,如果最长的路径长度 \(\geq \f…

---恢复内容开始--- output standard output The final match of the Berland Football Cup has been held recently. The referee has shown n yellow cards throughout the match. At the beginning of the match there were a_1 players in the first team and a_2 players…

这个题目其实很简单,有很多的方法写,然后我还是不会写,感觉自己好菜, 我开始想的是dp,但是不知道怎么dp,看了网上题解,豁然开朗 dp[i] 表示前面i个数满足条件的数有多少,f[s]表示前缀和为s的最大的满足条件的数 if(a[i]==0) dp[i]=dp[i-1]+1; else dp[i]=max(dp[i-1],f[s]+1) 知道这些就很简单了. #include <cstdio> #include <cstdlib> #include <cstring>…

题意:给你一个巨长无比的数,你可以将这个数划成任意多个部分,求这些部分中最多有多少个能被\(3\)整除. 题解:首先我们遍历累加每个位置的数字,如果某一位数或者累加和能被\(3\)整除(基础知识,不会就去百度),那这就是一部分,再来,我们可以发现一个部分最长只有\(3\)个数字. 证:当我这个部分有\(3\)个数字的时候,前两个数字\(mod\ 3\)的余数肯定同时为\(1\)或\(2\),这个时候: 假如第三个数字\(mod\ 3=1\)且前两个数字\(mod\ 3 = 1\),那这个三个数加…

//B. Delete from the Left #include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #include <set> #include <map> #include <vector> using namespace std; const int inf=0x3f3f3f3f; ; char a[N],b[…

本节主要内容: 1.正则表达式 2.re模块的使用 一.正则表达式 正则表达式,又称规则表达式.(英语:Regular Expression,在代码中常简写为regex.regexp或RE), 计算机科学的一个概念.正则表达式通常被用来检索.替换那些符合某个模式(规则)的文本. 正则表达式是对字符串操作的一种逻辑公式.我们一般使用正则表达式对字符串进行匹配和过滤.使用正则的优缺点: 优点: 灵活,功能性强,逻辑性强. 缺点:上手难. 工具:各大文本编辑器一般都有正则匹配功能.也可去 http:/…

思维题--code forces round# 551 div.2 题目 D. Serval and Rooted Tree time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Now Serval is a junior high school student in Japari Middle School, and he is…

题目传送门 /* 题意:套娃娃,可以套一个单独的娃娃,或者把最后面的娃娃取出,最后使得0-1-2-...-(n-1),问最少要几步 贪心/思维题:娃娃的状态:取出+套上(2),套上(1), 已套上(0),先从1开始找到已经套好的娃娃层数, 其他是2次操作,还要减去k-1个娃娃是只要套上就可以 详细解释:http://blog.csdn.net/firstlucker/article/details/46671251 */ #include <cstdio> #include <algor…

[Educational Codeforces Round 81 (Rated for Div. 2)]E. Permutation Separation(线段树,思维,前缀和) E. Permutation Separation time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given a permutat…

& -- 位运算之一,有0则0 原题链接 Problem - 1514B - Codeforces 题目 Example input 2 2 2 100000 20 output 4 226732710 题意 t个测试样例,在每个样例中 数组有n个数,数字范围[ 0, 2k - 1] 使得数组每个数&后,结果=0,并且这n个数的和要尽量大 输出有多少个这样的数组 解析 数组每个数&后,结果=0  -->每一位至少一个0 数要尽量大  -->只要这一位可以 != 0, 就…

C. Alyona and mex Problem Description: Alyona's mother wants to present an array of n non-negative integers to Alyona. The array should be special. Alyona is a capricious girl so after she gets the array, she inspects m of its subarrays. Subarray is…

C. Polycarp at the Radio time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Polycarp is a music editor at the radio station. He received a playlist for tomorrow, that can be represented as a…

题目链接 这个题取模的时候挺坑的!!! 题意:div(x , b) / mod(x , b) = k( 1 <= k <= a).求x的和 分析: 我们知道mod(x % b)的取值范围为 1  - (b-1).那么我们可以从这一点入口来进行解题.. mod (x, b) = 1 时, x  =  b + 1, 2b + 1, 3b + 1..... a * b + 1. mod (x , b) = 2 时, x =  2b + 2, 4b + 2, 6b + 2, ..... 2a * b…

题目链接: 题目 F. Polycarp and Hay time limit per test: 4 seconds memory limit per test: 512 megabytes input: standard input output: standard output 问题描述 The farmer Polycarp has a warehouse with hay, which can be represented as an n × m rectangular table,…

A. The Useless Toy time limit per test:1 second memory limit per test:256 megabytes input:standard input output:standard output Walking through the streets of Marshmallow City, Slastyona have spotted some merchants selling a kind of useless toy which…

Problem   Codeforces Round #539 (Div. 2) - D. Sasha and One More Name Time Limit: 1000 mSec Problem Description Input The first line contains one string s (1≤|s|≤5000) — the initial name, which consists only of lowercase Latin letters. It is guarante…

Problem   Codeforces Round #539 (Div. 2) - C. Sasha and a Bit of Relax Time Limit: 2000 mSec Problem Description Input The first line contains one integer n (2≤n≤3⋅10^5) — the size of the array. The second line contains n integers a1,a2,…,an (0≤ai<2^…

https://codeforces.com/contest/1136/problem/D 贪心 + 思维 题意 你面前有一个队列,加上你有n个人(n<=3e5),有m(m<=个交换法则,假如u在v相邻前面,那么u和v可以交换位置,问你是队列最后一个人的时候你最前可以换到前面哪里 题解 因为相邻才能换,所以最后一个换到前面一定是一步一步向前走,所以不存在还要向后走的情况 设最后一个为u,假设前面有一个能和u换位置的集合,那么需要将这些点尽量往后移动去接u 假设前面有一个不能和u换位置的集合S,…

F. Polycarp and Hay 题目连接: http://www.codeforces.com/contest/659/problem/F Description The farmer Polycarp has a warehouse with hay, which can be represented as an n × m rectangular table, where n is the number of rows, and m is the number of columns…

Problem  Codeforces Round #556 (Div. 2) - D. Three Religions Time Limit: 1000 mSec Problem Description Input Output Sample Input 51 2 1 2 1 Sample Output 1 1 1 2 2 题解:这个题有做慢了,这种题做慢了和没做出来区别不大... 读题的时候脑子里还意识到素数除了2都是奇数,读完之后就脑子里就只剩欧拉筛了,贪心地构造使得前缀和是连续的素数,那…