Description One particularly well-known fact about zombies is that they move and think terribly slowly. While we still don't know why their movements are so sluggish, the problem of laggy thinking has been recently resolved. It turns out that the rea…
题目描述 Brain Network (hard) 这个问题就是给出一个不断加边的树,保证每一次加边之后都只有一个连通块(每一次连的点都是之前出现过的),问每一次加边之后树的直径. 算法 每一次增加一条边之后,树的直径长度要么不变,要么会增加1,并且如果树的直径长度增加1了,新的直径的端点其中一个必然是新增的点,而另一个是原来直径的某个端点.关于为什么可以这样做,在Quora上有个回答解释地不错,可以参考. 实现 所以这个问题其实就是要计算树上任意两个点的距离,LCA可以很轻松地处理. 可以一次…
Description Tonight is brain dinner night and all zombies will gather together to scarf down some delicious brains. The artful Heidi plans to crash the party, incognito, disguised as one of them. Her objective is to get away with at least one brain,…
Description Heidi has finally found the mythical Tree of Life – a legendary combinatorial structure which is said to contain a prophecy crucially needed to defeat the undead armies. On the surface, the Tree of Life is just a regular undirected tree w…
Description The zombies are gathering in their secret lair! Heidi will strike hard to destroy them once and for all. But there is a little problem... Before she can strike, she needs to know where the lair is. And the intel she has is not very good.…
Description Further research on zombie thought processes yielded interesting results. As we know from the previous problem, the nervous system of a zombie consists of n brains and m brain connectors joining some pairs of brains together. It was obser…
Description "The zombies are lurking outside. Waiting. Moaning. And when they come..." "When they come?" "I hope the Wall is high enough." Zombie attacks have hit the Wall, our line of defense in the North. Its protection is…
http://codeforces.com/contest/1184 A1 找一对整数,使x^x+2xy+x+1=r 变换成一个分式,保证整除 #include<iostream> #include<cstdio> #include<string> #include<cstring> #include<algorithm> #include<cmath> #include<queue> #include<vector…
来自FallDream的博客,未经允许,请勿转载,谢谢, 第一次在cf上打acm...和同校大佬组队打 总共15题,比较鬼畜,最后勉强过了10题. AB一样的题目,不同数据范围,一起讲吧 你有一个背包,最多装k本书,你在第i天需要拥有一本编号ai的书,但是你可以去商店购买并加入背包. 问你至少要买多少本书?n,k<=400000 显然可以贪心,留下下一次需要的时间最早的书就行了. #include<iostream> #include<cstdio> #include<…
第一次打ACM赛制的团队赛,感觉还行: 好吧主要是切水题: 开场先挑着做五道EASY,他们分给我D题,woc什么玩意,还泊松分布,我连题都读不懂好吗! 果断弃掉了,换了M和J,然后切掉了,看N题: loser大佬切了A,G: 然后翔哥在攻H题: N题好像是费用流,(看了一会才发现的我果断被同在机房打比赛的别的队的大佬D了233) 然后写出了之后,那个大佬说费用流T了,交都没交就弃掉了: (事后才知道大概是图建的不好) loser大佬B题写的差不多了,交上去WA... 翔哥在攻H题: 我开始看K题…