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…

https://codeforces.com/contest/1118/problem/F1 #include<bits/stdc++.h> using namespace std; int n; vector<int> color; vector<vector<int> > tree; ,blue=; ; pair<){ ); ); ;i<tree[v].size();i++){ int u=tree[v][i]; if(u!=p){//避免回…

传送门:http://codeforces.com/contest/1092/problem/F F. Tree with Maximum Cost time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given a tree consisting exactly of nn vertices. Tree is a…

题意:有一组数,每次操作可以将某个数移到头部或者尾部,问最少操作多少次使得这组数非递减. 题解:先离散化将每个数映射为排序后所对应的位置,然后贪心,求最长连续子序列的长度,那么最少的操作次数一定为\(n-len\). 感觉不好解释,直接上图,其实就是排序后它们一定是连续的,所以我们就求一个最长的连续的,然后s剩下的数移到头部尾部,贪心的想,这样一定是最优解. 代码: #include <iostream> #include <cstdio> #include <cstring…

一 题面 C2. Increasing Subsequence (hard version) 二 分析 需要思考清楚再写的一个题目,不能一看题目就上手,容易写错. 分以下几种情况: 1 左右两端数都小于等于构造的数组的最后一个数字 2 左右两端数至少有一个大于构造的数组最后一个数字 a. 左右两端数字相等,肯定满足上面条件.那么只可能走一个方向,两边都模拟一下,比一下大小即可 b. 左右两端数组不等,则优先看谁满足上面2的情况,若都满足则选最小的 三 AC代码 #include <bits/st…

传送门:http://codeforces.com/contest/1105/problem/C C. Ayoub and Lost Array time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Ayoub had an array aa of integers of size nn and this array had two…

比赛链接:https://codeforces.com/contest/1445 A. Array Rearrangment 题意 给定两个大小均为 \(n\) 的升序数组 \(a\) 和 \(b\) ,判断能否重排数组 \(b\) 使得对任意 \(i\) 均满足 \(a_i + b_i \le x\) . 题解一 因为 \(a\) 为升序,所以将 \(b\) 按照降序排列判断即可. 代码 #include <bits/stdc++.h> using namespace std; int ma…

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…

A. Appleman and Easy Task time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Toastman came up with a very easy task. He gives it to Appleman, but Appleman doesn't know how to solve it. Can you…

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 try to clean up his house again. He…