D. Longest Subsequence 题目连接: http://www.codeforces.com/contest/632/problem/D Description You are given array a with n elements and the number m. Consider some subsequence of a and the value of least common multiple (LCM) of its elements. Denote LCM a…

D - Longest Subsequence 思路:枚举lcm, 每个lcm的答案只能由他的因子获得,类似素数筛搞一下. #include<bits/stdc++.h> #define LL long long #define fi first #define se second #define mk make_pair #define pii pair<int,int> #define piii pair<int, pair<int,int> > usi…

D. Longest k-Good Segment 题目连接: http://www.codeforces.com/contest/616/problem/D Description The array a with n integers is given. Let's call the sequence of one or more consecutive elements in a segment. Also let's call the segment k-good if it conta…

https://codeforces.com/contest/1132/problem/F 思维 + 区间dp 题意 给一个长度为n的字符串(<=500),每次选择消去字符,连续相同的字符可以同时消去,问最少需要消去多少次 题解 定义dp[l][r]为区间[l,r]剩下一个字符所需要的最小次数 dp[l][r]=min(dp[l][i]+dp[i+1][r]+x) x为消去剩下两个字符所需要的次数,假如两个字符相同需要x=-1 代码 #include<bits/stdc++.h> #de…

https://codeforces.com/contest/1051/problem/D 题意 一个2*n的矩阵,你可以用黑白格子去填充他,求联通块数目等于k的方案数,答案%998244353. 思路 按列dp,定义状态dp[i][j][k]为前i列,有j个联通块,最后一列为k的方案数 处理出列状态之间的转移(会新产生多少个新的联通块) 注意初始化问题 #include<bits/stdc++.h> #define P 998244353 #define ll long long using…

题目链接:http://codeforces.com/contest/598/problem/E E. Chocolate Bar time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You have a rectangular chocolate bar consisting of n × m single squares. Y…

题目链接:http://codeforces.com/contest/762/problem/D 多多分析状态:这个很明了 #include<bits/stdc++.h> using namespace std; #pragma comment(linker, "/STACK:102400000,102400000") #define ls i<<1 #define rs ls | 1 #define mid ((ll+rr)>>1) #define…

题目链接 题意:给你两个数n,m,和一个大小为n的数组. 让你在数组找一些数使得这些数的和模m最大. 解法:考虑 dfs但是,数据范围不允许纯暴力,那考虑一下折半搜索,一个从头开始往中间搜,一个从后往中间搜.在中间相遇的时间二分更新最大值即可. #include<bits/stdc++.h> #define LL long long #define fi first #define se second #define mp make_pair #define pb push_back usin…

Educational Codeforces Round 39  D. Timetable 令\(dp[i][j]\)表示前\(i\)天逃课了\(j\)节课的情况下,在学校的最少时间 转移就是枚举第\(i\)天逃了\(x\)节课,然后取当天逃\(x\)节课情况下在学校的最小值即可 view code #pragma GCC optimize("O3") #pragma GCC optimize("Ofast,no-stack-protector") #include…

Educational Codeforces Round 63 (Rated for Div. 2) D. Beautiful Array time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given an array aa consisting of nn integers. Beauty of array i…