WZJRJ28

题意:10^5的数列,让你交换两个数,使得交换后的数列的连续区间最大和最大。分析:我们假设最优解是交换u 和 v,u >= v,那么交换后的最优解应该是以交换后u向左右两端分别扩展的一段区间,和u之前位置异侧的最大扩展值可以O（n）的DP预处理出来,然后我们考虑和u之前位置（也就是v现在的位置）同侧的最大扩展区间,可以证明在原数列中u一定是这个扩展区间终点再往后/前的最大值,所以我们考

Problem DescriptionA boy named List who is perfect in English. Now he wants to travel and he is making a plan. But the cost of living in same citie always changes. Now he wants to know how many diff

B. Recover the Stringtime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard outputFor each string s consisting of characters '0' a

题意：给一棵树，m个黑点和一个K，问最长的不超过k个黑点的带权路径。分析：树上的点分治，被卡了一天，因为宏定义出现了神奇的错误。#include#include#include#include#include#include#include#include#include#include#include#define INF 0x3f3f3f3f#d

题意：给定一个r*c的键盘，键盘由字母和数字还有一些符号的按键组成，键盘光标的起始位置在左上角，每次移动可以朝上下左右四个方向跳到一个和当前位置字符不同的按键处，给定一串长字符，问至少要按多少次键盘。分析：直接BFS，f[i][j][k]表示当前在(i,j)位置，已经按了k个键的最小值。#include#include#include#include#include

DescriptionFor each integer i from 1 to n, you must print a string si of length n consisting of letters ‘a’ and ‘b’ only. The string si must contain exactly i distinct palindrome substrings. Two sub

题意： n 个人对m个方案投票 。 每个人最多对4个方案投票， 问是否存在一种决定  ， 使每个人都有超过一半的建议被采用 。 且哪些方案的态度是确定的。分析：投票数#include#include#include#include#include#include#include#include#include#include#include#inc

DescriptionA balanced number is a non-negative integer that can be balanced if a pivot is placed at some digit. More specifically, imagine each digit as a box with weight indicated by the digit. W

题意：给你一个n位”数“（前导0也算数字），问小于它的数字有多少，其中小于号重载为：1.a各个位上的数字和小于b.2.1相等的前提下a各个位上的数字+1相乘小于b.3.1，2相等的前提下a的十进制意义小于b。分析：

Problem DescriptionYou are given an array A, consisting of N integers.You are also given 2 integers K and L.You must divide the whole array A into exactly K nonempty intervals, such that the

A tree is an undirected connected graph without cycles.Let's consider a rooted undirected tree with n vertices, numbered1 through n. There are many ways to represent such a tree. One way is to cre

Problem DescriptionRecently, Bob has just learnt a naive sorting algorithm: merge sort. Now, Bob receives a task from Alice.Alice will give Bob N sorted sequences, and the i-th sequence includ

题意： 有n（nB表示A必须在B之前完成，A-B表示A和B不能在同一天晚上。输入保证约束图是将一颗树的一些边定向之后得到的。分析：     这题好神，我一开始根据题目的提示想了个错误的贪心，然后疯狂WA了一天。    我一开始错误的贪心是认为对于原图最长链k大于2的情况，答案为k+1当且仅当只有一个无向边定向后参与入了新的最长链的构造，于是我一开始的做法就是特判k = 2的情况

Matryoshka is a traditional Russian recursive doll. But everything changes, and even matryoshka needs a little innovation.Due to the use of new materials, it became possible to make a matryoshka arbit

Dear Liao I never forget the moment I met with you. You carefully asked me: "I have a very difficult problem. Can you teach me?". I replied with a smile, "of course". You replied:"Given a matrix,

Pasha is a good student and one of MoJaK's best friends. He always have a problem to think about. Today they had a talk about the following problem.We have a forest (acyclic undirected graph) with

题意:给你一个线段,问线段上有多少个整点.分析:我们先把直线的一般式搞出来,ax+by=c的形式,然后用欧扩求出直线一个整数点,设其横标为x,那么答案就是floor((x2-x)/b') - ceil((x1-x)/b') + 1. (x2 >= x1, b' = b/gcd(a,b)).#include #define INF 1047483647#define ep

Little boy Igor wants to become a traveller. At first, he decided to visit all the cities of his motherland — Uzhlyandia.It is widely known that Uzhlyandia has n cities connected with m bidirectio

After his birthday party, Timofey went to his favorite tree alley in a park. He wants to feed there his favorite birds — crows.It's widely known that each tree is occupied by a single crow family.

Princess Twilight went to Celestia and Luna's old castle to research the chest from the Elements of Harmony.A sequence of positive integers bi is harmony if and only if for every two elements

Description有N个未知数x[1..n]和N个等式组成的同余方程组：x[i]=k[i]*x[p[i]]+b[i] mod 10007其中，k[i],b[i],x[i]∈[0,10007)∩Z你要应付Q个事务，每个是两种情况之一：一.询问当前x[a]的解A a无解输出-1x[a]有多解输出-2否则输出x[a]二.修改一个等式C a k[a] p

题意：给一棵带权树,问每个点和所有标号小于它的点的带权lca和。分析：这种lca和可以看成是两段权值不同的链的差，这样我们用lct来维护树上每段链的带权重量和，每次插入一个点。#include#include#include#include#include#include#include#include#include#include#include#

Given a simple graph, output the number of simple cycles in it. A simple cycle is a cycle with no repeated vertices or edges.InputThe first line of input contains two integers n and m (1 ≤ n ≤ 19,

There are n workers in a company, each of them has a unique id from1 to n. Exaclty one of them is a chief, his id is s. Each worker except the chief has exactly one immediate superior.There was

题意：给定一个n个点m条边的加权有向图，求平均权值最小的回路。分析：二分+负权回路的判断，数据居然有自环，MDZZ,WA了一晚上。#include #include #include #include #include #include #include #include #include #defi

描述在经过一段时间的经营后，dd_engi的OI商店不满足于从别的供货商那里购买产品放上货架，而要开始自己生产产品了！产品的生产需要M个步骤，每一个步骤都可以在N台机器中的任何一台完成，但生产的步骤必须严格按顺序执行。由于这N台机器的性能不同，它们完成每一个步骤的所需时间也不同。机器i完成第j个步骤的时间为T[i,j]。把半成品从一台机器上搬到另一台机器上也需要一定的时间K。同时，为了保证

First-rate specialists graduate from Berland State Institute of Peace and Friendship. You are one of the most talented students in this university. The education is not easy because you need to have f

Famous abstract painter Va Sya plans to start new painting. It will be composed as square with gridn × n, where each unit square is painted by some color.Va Sya already defined the colors for some unit squares. Color of other squares does not matter for h

Time Limit: 1000MS Memory Limit: 30000KTotal Submissions: 24046 Accepted: 5947DescriptionImagine you are attending your math lesson at school. Once again, you are bored because

AirportA big city has an international airport handling 40 million passengers a year. But this is notorious as one of the most congested airports in the world. In this airport, there is only one lan

A sweet little monster Om Nom loves candies very much. One day he found himself in a rather tricky situation that required him to think a bit in order to enjoy candies the most. Would you succeed with

Time Limit: 1000MS Memory Limit: 10000KTotal Submissions: 13871 Accepted: 4932Description将一个８*８的棋盘进行如下分割：将原棋盘割下一块矩形棋盘并使剩下部分也是矩形，再将剩下的部分继续如此分割，这样割了(n-1)次后，连同最后剩下的矩形棋盘共有n块矩形棋

DescriptionConsider two natural numbers A and B. Let S be the sum of all natural divisors of A^B. Determine S modulo 9901 (the rest of the division of S by 9901).InputThe only line contains the

time limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputIn the school computer room there are n servers which are responsible for

Time Limit: 2000MS Memory Limit: 65536KTotal Submissions: 3740 Accepted: 1724DescriptionFarmer John has arranged his N (1 ≤ N ≤ 5,000) cows in a row and many of them are fa

time limit per test4 seconds (5 seconds for Java)memory limit per test256 megabytesinputstandard inputoutputstandard outputFor each vertice of given undirected weighted graph c

Problem DescriptionHere is a famous story in Chinese history."That was about 2300 years ago. General Tian Ji was a high official in the country Qi. He likes to play horse racing with the king

It was recycling day in Kekoland. To celebrate it Adil and Bera went to Central Perk where they can take bottles from the ground and put them into a recycling bin.We can think Central Perk as coordi

DescriptionThe young and very promising cryptographer Odd Even has implemented the security module of a large system with thousands of users, which is now in use in his company. The cryptographic

题意：有n个骑士经常举行圆桌会议，商讨大事，每次圆桌会议至少应有3个骑士参加，且互相憎恨的骑士不能坐在圆桌旁的相邻位置，如果发生意见分歧，则需要举手表决，因此参加会议的骑士数目必须是奇数，以防赞同和反对票一样多，知道哪些骑士互相憎恨之后，你的任务是统计有多少个骑士不可能参加任何一个会议。分析：求出原图的补图后，问题转化为判断一个点是否存在一个奇数环内，一个环内的所有点一定在同一个点双联