链接: https://codeforces.com/contest/1221/problem/D 题意: You have a fence consisting of n vertical boards. The width of each board is 1. The height of the i-th board is ai. You think that the fence is great if there is no pair of adjacent boards having…

传送门 A. 2048 Game 乱搞即可. Code #include <bits/stdc++.h> #define MP make_pair #define fi first #define se second #define sz(x) (int)(x).size() //#define Local using namespace std; typedef long long ll; typedef pair<int, int> pii; const int N = 1e5…

链接: https://codeforces.com/contest/1221/problem/B 题意: You are given a chess board with n rows and n columns. Initially all cells of the board are empty, and you have to put a white or a black knight into each cell of the board. A knight is a chess pi…

链接: https://codeforces.com/contest/1221/problem/C 题意: You may have already known that a standard ICPC team consists of exactly three members. The perfect team however has more restrictions. A student can have some specialization: coder or mathematici…

链接: https://codeforces.com/contest/1221/problem/A 题意: You are playing a variation of game 2048. Initially you have a multiset s of n integers. Every integer in this multiset is a power of two. You may perform any number (possibly, zero) operations wi…

这道题里线段树用来区间更新(每次给更大的区间加上当前区间的权重),用log的复杂度加快了更新速度,也用了区间查询(查询当前区间向右直至最右中以当前区间端点向右一段区间的和中最大的那一段的和),也用log的复杂度加快了查询速度. #define HAVE_STRUCT_TIMESPEC #include<bits/stdc++.h> using namespace std; ],y[]; ]; ]; vector<pair<]; ],lz[],mxid[]; long long cm…

//这道题博弈的核心就是不能让后手有一段只能放b而长度不够放a的段,并且先手要放最后一次#define HAVE_STRUCT_TIMESPEC#include<bits/stdc++.h>using namespace std;int length[300007];int main(){ ios::sync_with_stdio(false);//多组数据输入cin,cout容易超时 cin.tie(NULL); cout.tie(NULL); int q; cin>>q; wh…

#define HAVE_STRUCT_TIMESPEC#include<bits/stdc++.h>using namespace std;long long a[300007],b[300007];long long dp[300007][5];long long ans;int main(){ ios::sync_with_stdio(false);//多组数据输入cin,cout容易超时 cin.tie(NULL); cout.tie(NULL); int q; cin>>…

题意就是给出多个区间,要求去掉两个区间,使得剩下的区间覆盖范围最大. 当然比赛的时候还是没能做出来,不得不佩服大佬的各种姿势. 当时我想的是用线段树维护区间和,然后用单点判0,维护区间间断个数.然后打到一半,就发现想法有问题. 这道题正解就是简单的前缀和,或者DP. 我为了更加深入理解,两种方法都试了试. 前缀和版本: 由于题目给的范围是5000,明显支持N^2,于是我们枚举去掉的两个,刚好满足,那么要如何才能O(1)的得到答案? 我们其实可以这样,我们知道它的总覆盖的数目,这是非常容易求出的.…

D. Yet Another Subarray Problem You are given an array \(a_1, a_2, \dots , a_n\) and two integers \(m\) and \(k\). You can choose some subarray \(a_l, a_{l+1}, \dots, a_{r-1}, a_r\). The cost of subarray \(a_l, a_{l+1}, \dots, a_{r-1}, a_r\) is equal…