人生第二场codeforces.然而遇上了Education场这种东西 Educational Codeforces Round 40 下午先在家里睡了波觉,起来离开场还有10分钟. 但是突然想起来还没报名呢,并且电脑又是开机黑屏什么情况 莫非为之后的凉凉埋下了伏笔? 比赛之前联系了下余翱和叶可禾,似乎都要去切题的样子? 想到第一次有人一起打CF还是有点小激动的.于是果断屏蔽余翱QQ上的刷屏去看A题了. A. Diagonal Walking 非常仔细地把题读了一遍,然后……啥这不是字符串入门题…

Educational Codeforces Round 40 F. Runner's Problem 题意: 给一个$ 3 * m \(的矩阵,问从\)(2,1)$ 出发 走到 \((2,m)\) 的方案数 \(mod 1e9 + 7\), 走的规则和限制如下: From the cell (i, j) you may advance to: (i - 1, j + 1) - only if i > 1, (i, j + 1), or (i + 1, j + 1) - only if i <…

Educational Codeforces Round 40 (Rated for Div. 2) C. Matrix Walk time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output There is a matrix A of size x × y filled with integers. For every , *A**i, …

题 OvO http://codeforces.com/contest/954/problem/G 解 二分答案, 对于每个二分的答案值 ANS,判断这个答案是否可行. 记 s 数组为题目中描述的 a 数组 以下为初始化: 首先建一个 个元素到第 i 个元素的和 然后建一个 p 数组,其中 p[i] 代表能射到第 i 个区域的弓箭手数量, p[i] 显然可以由 pre 计算得到 以下是对于二分的每个答案值 ANS,判断这个值是否可行的做法: 创建一个 d 数组, d[i] = p[i] - p[…

从这里开始 小结 题目列表 Problem A Diagonal Walking Problem B String Typing Problem C Matrix Walk Problem D Fight Against Traffic Problem E Water Taps Problem F Runner's Problem Problem G Castle Defense Problem H Path Counting Problem I Yet Another String Match…

http://codeforces.com/contest/954/problem/I 给你两个串s,p,求上一个串的长度为|p|的所有子串和p的差距是多少,两个串的差距就是每次把一个字符变成另一个字符的最小次数,字符最大到f 很明显,如果知道每两个串对应地方不相同的字符就能通过dfs/dsu解出来,那么如何快速的找到所有对应的不匹配的地方呢, 我们先单独考虑两个不同的字符,比如abada中取a,cba中取c,用二进制1代表选取的字符表示就是10101,100,我们用fft来加速这一过程 1 2…

G. Castle Defense time limit per test 1.5 seconds memory limit per test 256 megabytes input standard input output standard output Today you are going to lead a group of elven archers to defend the castle that is attacked by an army of angry orcs. Thr…

A. Diagonal Walking 题意 将一个序列中所有的\('RU'\)或者\('UR'\)替换成\('D'\),问最终得到的序列最短长度为多少. 思路 贪心 Code #include <bits/stdc++.h> #define F(i, a, b) for (int i = (a); i < (b); ++i) #define F2(i, a, b) for (int i = (a); i <= (b); ++i) #define dF(i, a, b) for (…

A. Diagonal Walking time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Mikhail walks on a 2D plane. He can go either up or right. You are given a sequence of Mikhail's moves. He thinks that th…

Educational Codeforces Round 64 部分题解 不更了不更了 CF1156D 0-1-Tree 有一棵树,边权都是0或1.定义点对\(x,y(x\neq y)\)合法当且仅当树上\(x\)到\(y\)的路径权值是一段0接一段1.求合法点对数量. 直接点分治 我是傻逼居然还写了50min... https://codeforces.com/contest/1156/submission/53661175 CF1156E Special Segments of Permut…

Educational Codeforces Round 61 今早刚刚说我适合打pikmike出的EDU 然后我就挂了 A 不管 B 不管 C 这道题到快结束了才调出来 大概就是\(n^2\)枚举不选的区间 然后随便搞搞? 大体就是维护一下区间\(1\)的个数和\(2\)的个数 判断枚举的区间有没有交集 这个的答案就是并集1的个数和交集2的个数 用总的减去更新就好了 另外如果一个区间被另外一个区间完全包含 那么这个区间肯定是没用的 特判一下就好了 #include<cstdio> #incl…

UPD:变色了!!!历史最高1618~ Educational Codeforces Round 81 (Rated for Div. 2) The 2019 University of Jordan Collegiate Programming Contest   充实的一天,打两场可还行.补的一些题记录一下. edu81 Educational Codeforces Round 81 (Rated for Div. 2) 还不知道上分还是掉分,还挺可惜的,被B卡了没做出来,C也调了一会儿答案…

Educational Codeforces Round 17 A. k-th divisor 水题,把所有因子找出来排序然后找第\(k\)大 view code //#pragma GCC optimize("O3") //#pragma comment(linker, "/STACK:1024000000,1024000000") #include<bits/stdc++.h> using namespace std; function<voi…

[Educational Codeforces Round 16]E. Generate a String 试题描述 zscoder wants to generate an input file for some programming competition problem. His input is a string consisting of n letters 'a'. He is too lazy to write a generator so he will manually ge…

[Educational Codeforces Round 16]D. Two Arithmetic Progressions 试题描述 You are given two arithmetic progressions: a1k + b1 and a2l + b2. Find the number of integers x such that L ≤ x ≤ R andx = a1k' + b1 = a2l' + b2, for some integers k', l' ≥ 0. 输入 Th…

[Educational Codeforces Round 16]C. Magic Odd Square 试题描述 Find an n × n matrix with different numbers from 1 to n2, so the sum in each row, column and both main diagonals are odd. 输入 The only line contains odd integer n (1 ≤ n ≤ 49). 输出 Print n lines…

[Educational Codeforces Round 16]B. Optimal Point on a Line 试题描述 You are given n points on a line with their coordinates xi. Find the point x so the sum of distances to the given points is minimal. 输入 The first line contains integer n (1 ≤ n ≤ 3·105)…

[Educational Codeforces Round 16]A. King Moves 试题描述 The only king stands on the standard chess board. You are given his position in format "cd", where c is the column from 'a' to 'h' and dis the row from '1' to '8'. Find the number of moves perm…

Educational Codeforces Round 6 C. Pearls in a Row 题意:一个3e5范围的序列:要你分成最多数量的子序列,其中子序列必须是只有两个数相同, 其余的数只能出现一次. 策略: 延伸:这里指的延伸如当发现1-1如果以最后出现重叠的数为右边界则就表示左延伸,若以1.0.1..0第二个0前一个位置作为右边界就为右延伸: 开始时想是右延伸,考虑到可能只出现一组两个数相同,认为向左延伸会出错,但是直接WA了之后,发现这并不是题目的坑点(其实只需将最后一组改成左右…

Educational Codeforces Round 9 Longest Subsequence 题目描述:给出一个序列,从中抽出若干个数,使它们的公倍数小于等于\(m\),问最多能抽出多少个数,并输出方案与公倍数. solution 枚举每一个数,将它的倍数的答案加一,最大值就是答案. 时间复杂度:\(O(nlogn)\) Thief in a Shop 题目描述:给出\(n\)中物品与它们的价值,每种物品都有无限个,问从中拿出\(m\)个,价值有可能是什么,输出所有的价值. soluti…

Educational Codeforces Round 37 这场有点炸,题目比较水,但只做了3题QAQ.还是实力不够啊! 写下题解算了--(写的比较粗糙,细节或者bug可以私聊2333) A. Water The Garden 题意:给你一个长度为\(n\)的池子,告诉你哪些地方一开始有水, 每秒可以向左和向右增加一格的水, 问什么时候全部充满水.(\(n \le 200\)) 题解:按题意模拟.每次进来一个水龙头,就更新所有点的答案 (取\(min\)).最 后把所有点取个\(max\)就…

Problem   Educational Codeforces Round 60 (Rated for Div. 2) - C. Magic Ship Time Limit: 2000 mSec Problem Description Input Output The only line should contain the minimal number of days required for the ship to reach the point (x2,y2)(x2,y2). If it…

Problem   Educational Codeforces Round 60 (Rated for Div. 2) - D. Magic Gems Time Limit: 3000 mSec Problem Description Input The input contains a single line consisting of 2 integers N and M (1≤N≤10^18, 2≤M≤100). Output Print one integer, the total n…

616A - Comparing Two Long Integers    20171121 直接暴力莽就好了...没什么好说的 #include<stdlib.h> #include<stdio.h> #include<math.h> #include<cstring> #include<iostream> #include<algorithm> using namespace std; string a,b;int sa,sb;…

Educational Codeforces Round 43 (Rated for Div. 2) https://codeforces.com/contest/976 A #include<bits/stdc++.h> using namespace std; #define lson l,mid,rt<<1 #define rson mid+1,r,rt<<1|1 #define IT set<ll>::iterator #define sqr(x)…

Educational Codeforces Round 35 (Rated for Div. 2) https://codeforces.com/contest/911 A 模拟 #include<bits/stdc++.h> using namespace std; #define lson l,mid,rt<<1 #define rson mid+1,r,rt<<1|1 #define IT set<ll>::iterator #define sqr(…

Codeforces Educational Codeforces Round 44 (Rated for Div. 2) F. Isomorphic Strings 题目连接: http://codeforces.com/contest/985/problem/F Description You are given a string s of length n consisting of lowercase English letters. For two given strings s an…

Codeforces Educational Codeforces Round 44 (Rated for Div. 2) E. Pencils and Boxes 题目连接: http://codeforces.com/contest/985/problem/E Description Mishka received a gift of multicolored pencils for his birthday! Unfortunately he lives in a monochrome w…

Educational Codeforces Round 63 (Rated for Div. 2)题解 题目链接 A. Reverse a Substring 给出一个字符串,现在可以对这个字符串进行一次翻转,问是否存在一种方案,可以使得翻转后字符串的字典序可以变小.   这个很简单,贪心下就行了. 代码如下: Code #include <bits/stdc++.h> using namespace std; typedef long long ll; const int N = 3e5…

这两道题都需要用到拓扑排序,所以先介绍一下什么叫做拓扑排序. 这里说一下我是怎么理解的,拓扑排序实在DAG中进行的,根据图中的有向边的方向决定大小关系,具体可以下面的题目中理解其含义 Educational Codeforces Round 25  E. Minimal Labels 题目链接:http://codeforces.com/contest/825/problem/E 题意:给你一个有向无环图(DAG),有n个顶点,m条边,顶点的序号分别是1-n,现在给你1-n的数对n个顶点进行赋值…