[CF845F]Guards In The Storehouse 题意:一个n*m的房间,每个格子要么是障碍要么是空地.对于每个空地你可以选择放或者不放守卫.一个守卫能保护到的位置是:他右面的一行空地+下面的一列空地,但是不能穿过障碍(可以穿过另一个守卫).现在要求至多有1个空地没有被保护,求放置守卫的方案数. $n\times m\le 250$ 题解:n和m中较小者不超过15,所以插头DP不解释~ #include <cstdio> #include <cstring> #in…

F. Guards In The Storehouse time limit per test 1.5 seconds memory limit per test 512 megabytes input standard input output standard output Polycarp owns a shop in the capital of Berland. Recently the criminal activity in the capital increased, so Po…

Beijing was once surrounded by four rings of city walls: the Forbidden City Wall, the Imperial City Wall, the Inner City Wall, and finally the Outer City Wall. Most of these walls were demolished in the 50s and 60s to make way for roads. The walls we…

Beijing Guards Beijing was once surrounded by four rings of city walls: the Forbidden City Wall, the Imperial City Wall, the Inner City Wall, and finally the Outer City Wall. Most of these walls were demolished in the 50s and 60s to make way for road…

题目链接:uva 1335 - Beijing Guards 题目大意:有n个人为成一个圈,其中第i个人想要r[i]种不同的礼物,相邻的两个人可以聊天,炫耀自己的礼物.如果两个相邻的人拥有同一种礼物,则双方都会很不高兴,问最少需要多少种不同的礼物才能满足所有人的需求,假设每种礼物有无限多个. 解题思路:自己想没有什么思路,参照大白书上的解释,琢磨了一下. 如果n为偶数的话,ans = max{r[i] + r[i + 1] },(r[n + 1] = r[1]). 如果n为奇数的话,上述式子就不…

UVA 11080 - Place the Guards 题目链接 题意:一些城市.之间有道路相连,如今要安放警卫,警卫能看守到当前点周围的边,一条边仅仅能有一个警卫看守,问是否有方案,假设有最少放几个警卫 思路:二分图判定,判定过程记录下白点和黑点个数,小的就是要安放的个数,注意假设是0,那么应该是加1 代码: #include <cstdio> #include <cstring> #include <vector> using namespace std; con…

题目大意:给定一个环,每个人要得到Needi种物品,相邻的人之间不能得到相同的,问至少需要几种. 首先把n=1特判掉. 然后在n为偶数的时候,答案就是max(Needi+Needi+1)(包括(1,n)). 证明:把物品排成一行,只要一个人从左边开始取,下一个人从右边开始取,以此类推,保证不会重复. 然后在n为奇数的时候,答案就不好做了. 观察一下这道题,发现答案满足可二分性,不如思考一下check怎么写. 因为n为奇数时难点就在看n与1是否矛盾上,只要解决了这个问题,一切好说. 不难发现答案下…

less guards/argument matching: .setbackground(@number) when (@number>0){ .setbackground( @number - 1 ); .class@{number} { background-image: ~"url(backgroundimage- @{number}.png)"; } } .setbackground(10); 输出以下css: .class1 { background-image: u…

In an unprecedented turn of events, goblins recently launched an invasion against the Nedewsian city of Mlohkcots. Goblins—small, green critters—love nothing more than to introduce additional entropy into the calm and ordered lives of ordinary people…

Note: I've compared , and ; in guards to the operators andalso and orelse. They're not exactly the same, though. The former pair will catch exceptions as they happen while the latter won't. What this means is that if there is an error thrown in the f…