[题解]At2370 Piling Up \[ dp(i,j,0/1) \\ 正在进行i项操作并且此时黑球剩下j个,黑球[0/1]数量曾经到过0 \\ 为什么加第二位,判重.怎么想到的? \] 非常神仙了.现在我做题基本上就是改编戏说了...自己是做不出来的,不管是只是层面还是思维层面的高度都不够. 那就一题一题地吸收吧. 其实问这样的\(dp\)设计是如何想到的,都是人们看清楚了方案重合的本[题解]At2370 Piling Up质是什么,然后就针对这个本质设计来的... 感觉这种设\(0/1…

https://www.luogu.org/jump/atcoder/2370 题解 答案不是\(2^{2m}\)因为每轮的第一次取球可能会不够. 我们可以设\(dp[i][j]\)表示到了第\(i\)轮,当前白球有\(j\)个的方案数. 转移的话枚举下一次拿球的方案. 白白:\((i,j)->(i+1,j-1)\) 黑黑:\((i,j)->(i+1,j+1)\) 白黑:\((i,j)->(i+1,j)\) 黑白:\((i,j)->(i+1,j)\) 把每个状态放在二维平面上的话,…

[题解]Counting D-sets(容斥+欧拉定理) 没时间写先咕咕咕. vjCodeChef - CNTDSETS 就是容斥,只是难了一二三四五\(\dots \inf\)点 题目大意: 给定你一个\(n\)维空间,问你这个空间内有多少个点集满足两点间最大的切比雪夫距离为\(d\).两个点集不同,当且仅当两个点集无法通过平移而想等. 转化1 考虑最后那个限制,平移想等的限制,受这道题的启发[题解]At2370 Piling Up,我们考虑钦定每一维的\(0\)点都有点坐落,这样就钦定了一个…

CF79D Password: 差分.两点取反,本质是匹配!最短路+状压DP 取反是套路,匹配是发现可以把操作进行目的化和阶段化,从而第二次转化问题. 且匹配不会影响别的位置答案 sequence 计算最长极长段小于等于j的方案数 突破口是i,k总共对数nlogn级别,干掉j用组合意义大力推导 CF1062F Upgrading Cities DAG考虑topo,关键性质:topo序队列中点两两不可达.只在队列长度<=2时候才关心. CF1060F Shrinking Tree 考虑x是不是rt…

[agc013d]Piling Up(动态规划) 题面 atcoder 洛谷 有\(n\)个球,颜色为黑白中的一种,初始时颜色任意. 进行\(m\)次操作,每次操作都是先拿出一个求,再放进黑白各一个,再拿出一个球. 求最终拿出球的序列的方案数. 题解 首先可以把操作看成每次拿出一个球把它染上任意一种颜色. 设\(f[i][j]\)表示进行完前\(i\)次操作,还剩下\(j\)个黑球的方案数. 拿出球的序列如果只从黑球的角度来看的话,可以看成一个\(+1,-1\)组成的折线. 如果折线能够到达的最…

CodeForces - 50A Domino piling (贪心+递归) 题意分析 奇数*偶数=偶数,如果两个都为奇数,最小的奇数-1递归求解,知道两个数都为1,返回0. 代码 #include <iostream> #include <cstdio> #include <algorithm> #include <cstring> #include <sstream> #include <set> #include <map…

题意简化: [luogu] Piling Up 一开始有n个颜色为黑白的球,但不知道黑白色分别有多少,m次操作,每次先拿出一个球,再放入黑白球各一个,再拿出一个球,最后拿出的球按顺序排列会形成一个颜色序列,求颜色序列有多少种 n,m小于等于3000 答案对1e9+7取膜 一些乱七八糟的东西 这个题还是 Power_Leo101 同学教我做的, 自己太弱了,完全不会 这是菊队ppt里推荐的题, 这个学期过了, 学长们就毕业了, 菊队也不再会给我们讲课了 虽然陈菊开学长讲课的画风毒瘤, ppt毒瘤…

背景:本项目使用JDK1.8 编译maven工程的时候出现如下错误: Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1 pom中如下配置maven插件,配置中声明使用JDK1.8: <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</…

题目链接:http://www.codeforces.com/problemset/problem/50/A题意:一个NxM的举行中最多能放多少个1x2的矩形.C++代码: #include <iostream> using namespace std; int main() { int n, m; cin >> n >> m; cout << (n * m) / << endl; ; } C++…

Problem description You are given a rectangular board of M × N squares. Also you are given an unlimited number of standard domino pieces of 2 × 1 squares. You are allowed to rotate the pieces. You are asked to place as many dominoes as possible on th…

题意 盒子里有n块砖,每块的颜色可能为蓝色或红色. 执行m次三步操作: 1.从盒子里随便拿走一块砖 2.放入一块蓝砖和红砖到盒子里 3.从盒子里随便拿走一块砖 给定n,m 问拿出来的砖,可能有多少种不同的颜色序列. n,m<=3000 解法 容易想到一个dp, 设f[i][j]表示已经执行了i次的操作,然后目前盒子里有j块蓝砖,和n-j块红砖. 共有四种转移,分别是一次操作拿走的砖头为红红.红蓝.蓝红.蓝蓝. 边界为f[0][0..n]=1 然后就会发现算重了, 这是因为不同的颜色序列可能会有不…

Perf简介 Perf是Linux kernel自带的系统性能优化工具.虽然它的版本还只是0.0.2,Perf已经显现出它强大的实力,足以与目前Linux流行的OProfile相媲美了. Perf 的优势在于与Linux Kernel的紧密结合,它可以最先应用到加入Kernel的new feature.而像OProfile, GProf等通常会“慢一拍”.Perf的基本原理跟OProfile等类似,也是在CPU的PMU registers中Get/Set performance counters…

Emptying the Second Stage Recycle Bin in SharePoint 2007   Look in your second stage recycle bin in SharePoint 2007.  If you see lots of items that are older than the configured policy (default is 30 days), then there are one of a few things happenin…

http://www.cgw.com/Publications/CGW/2012/Volume-35-Issue-4-June-July-2012/The-Royal-Treatment.aspx The Royal Treatment By: Barbara Robertson Pixars extraordinary run of successful films starring male characters took a courageous turn in June with the…

http://www.extremetech.com/computing/51994-the-naked-truth-about-anisotropic-filtering In the seemingly never-ending quest for more perfect 3D rendering, numerous filtering techniques are used to map an apparent three-dimensional shape into a 2D moni…

There are certain things to care while implementing the Jasper Reports for huge dataset to handle the memory efficiently, so that the appliacation does not go out of memory. They are: 1) Pagination of the data and use of JRDataSource, 2) Viruatizatio…

#瓦登尔湖词频统计: import string path = 'D:/python3/Walden.txt' with open(path,'r',encoding= 'utf-8') as text: words = [raw_word.strip(string.punctuation).lower() for raw_word in text.read().split()] words_index = set(words) counts_dict = {index:words.count(…

java has four types of garbage collectors, Serial Garbage Collector Parallel Garbage Collector CMS Garbage Collector G1 Garbage Collector 我们先说一下垃圾回收中常见的算法,以及实现的原理,这些都是如何发生的. Returning back to Garbage Collection, there is a term that you should know b…

Your website maybe stop working and response very lowly. How to find out the reason? Below are the guide, hope it will help you out! Identify it is a hang What website hang really means? An IIS website hangs whenever it appears to stop serving incomi…

The Contortion Brothers are a famous set of circus clowns, known worldwide for their incredible ability to cram an unlimited number of themselves into even the smallest vehicle. During the off-season, the brothers like to get together for an Annual C…

通过netstat -anp可以查看机器的当前连接状态:   Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name tcp        0      0 0.0.0.0:8139            0.0.0.0:*              …

Tomorrow never comes. 我生待明日,万事成蹉跎. Most of my past failures can be chalked up to the bad habit of procrastination. If I had accomplished every task timely, my life would be totally different. Every task has its own deadline and happen in its unique w…

Picnic Planning Time Limit: 5000MS   Memory Limit: 10000K Total Submissions:11615   Accepted: 4172 Description The Contortion Brothers are a famous set of circus clowns, known worldwide for their incredible ability to cram an unlimited number of them…

AGC013 A - Sorted Arrays 直接分就行 #include <bits/stdc++.h> #define fi first #define se second #define pii pair<int,int> #define mp make_pair #define pb push_back #define space putchar(' ') #define enter putchar('\n') #define eps 1e-10 #define MAX…

Climate change is a devilish problem for humanity: at once urgent and slow-moving, immediate and distant, real and abstract. It is a conundrum for writers, too. Relegating it to a human-interest story—a Bangladeshi displaced by rising sea levels, say…

之所以在codeforces上找这100道水题的原因是为了巩固我对最近学的编程语言的掌握程度. 找的方式在codeforces上的PROBLEMSET中过的题最多的那些题里面出现的最前面的10个题型,它们是: math(数学) brute force(暴力) strings(字符串) implementation(模拟) greedy(贪心) sortings(排序) number theory(数论) constructive algorithm dp(动态规划) shortest path(…

TEXT 3 Food firms and fat-fighters 食品公司与减肥斗士 Feb 9th 2006 From The Economist Global Agenda Five leading food companies have introduced a labelling scheme for their products in the British market, in an attempt to assuage critics who say they encourag…

Quick and dirty  快而脏的快餐 BEIJING  北京 Food delivery is a booming business. Waste is piling up, too  送餐是快速发展的行业,但同时产生了大量垃圾 THREE couriers[1] in hard helmets cram into[2] an office lift[3] in Beijing—one clad in[4] red, one in yellow and one in blue. The…

TPO 03 - Architecture Architecture is the art and science of designing structures that[主语是Architecture ] organize and enclose space for practical and symbolic purposes.[建筑为了实用性和象征性的目的,也是一种科学与艺术] Because architecture grows out of[grow out of 源自] human…

Description The Contortion Brothers are a famous set of circus clowns, known worldwide for their incredible ability to cram an unlimited number of themselves into even the smallest vehicle. During the off-season, the brothers like to get together for…