The only difference between easy and hard versions is constraints. There are nn kids, each of them is reading a unique book. At the end of any day, the ii-th kid will give his book to the pipi-th kid (in case of i=pii=pi the kid will give his book to…

题目链接:http://codeforces.com/problemset/problem/1249/B2 思路:用并查集模拟链表,把关系串联起来,如果成环,则满足题意.之后再用并查集合并一个链,一个链代表 一个集合,一个集合有共同的祖先,一个集合答案相同,则输出答案时候只需要输出该元素属于哪一个集合,那个集合有几个元素 就可以了. #include <stdio.h> #include <iostream> using namespace std; ; int fa[N]; in…

The only difference between easy and hard versions is constraints. There are nn kids, each of them is reading a unique book. At the end of any day, the ii-th kid will give his book to the pipi-th kid (in case of i=pii=pi the kid will give his book to…

G1 - Into Blocks (easy version) 参考:Codeforces Round #584 - Dasha Code Championship - Elimination Round (rated, open for everyone, Div. 1 + Div. 2) G1. Into Blocks (easy version) 思路:先把数据预处理一遍,找到每一种数的最右端的位置,和每一种数的出现的次数,然后,从第一个数字开始遍历,用r保存当前这一块的最大右端,用MAX…

就像title说的,是昨天(2017/9/17)周赛的两道水题…… 题目链接:http://codeforces.com/problemset/problem/14/A time limit per test: 1 second memory limit per test: 64 megabytes A boy Bob likes to draw. Not long ago he bought a rectangular graph (checked) sheet with n rows and…

任意门:http://codeforces.com/contest/1118/problem/F1 F1. Tree Cutting (Easy Version) time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given an undirected tree of nn vertices. Some vert…

任意门:http://codeforces.com/contest/1118/problem/D1 D1. Coffee and Coursework (Easy version) time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output The only difference between easy and hard versions…

F1. Pictures with Kittens (easy version) 题目链接:https://codeforces.com/contest/1077/problem/F1 题意: 给出n个数,以及k,x,k即长度为k的区间至少选一个,x的意思是一共要选x个,少一个或者多一个都不行. 选一个会得到一定的奖励,问在满足条件的前提下,最多得到多少的奖励. 题解: 简单版本数据量比较小,考虑比较暴力的动态规划. dp[i,j]表示前i个数,要选第i个数,目前选了j个所得到的最大奖励,那么当…

B1. Character Swap (Easy Version) This problem is different from the hard version. In this version Ujan makes exactly one exchange. You can hack this problem only if you solve both problems. After struggling and failing many times, Ujan decided to tr…

题目链接:Pictures with Kittens (easy version) 题意:给定n长度的数字序列ai,求从中选出x个满足任意k长度区间都至少有一个被选到的最大和. 题解:$dp[i][j]$:以i为结尾选择j个数字的最大和. $dp[i][j]=max(dp[i][j],dp[s][j-1]+a[i])$,$s为区间[i-k,i)$. 以i为结尾的最大和可以由i之前k个位置中的其中一个位置选择j-1个,再加上当前位置的ai得到. #include <cstdio> #includ…