Brain Network (medium) 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. I…

H - Brain Network (medium) Time Limit:2000MS     Memory Limit:262144KB     64bit IO Format:%I64d & %I64u CodeForces 690C2 Description Further research on zombie thought processes yielded interesting results. As we know from the previous problem, the…

题目链接: C2. Brain Network (medium) time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Further research on zombie thought processes yielded interesting results. As we know from the previous prob…

题意:给定一棵树中,让你计算它的直径,也就是两点间的最大距离. 析:就是一个树上DP,用两次BFS或都一次DFS就可以搞定.但两次的时间是一样的. 代码如下: #include<bits/stdc++.h> using namespace std; const int maxn = 1e5 + 5; vector<int> G[maxn]; int f[maxn], g[maxn], l[maxn]; int dfs(int root, int fa){ if(f[root] !=…

Brain Network (easy) 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 tha…

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…

G - Brain Network (easy) Time Limit:2000MS     Memory Limit:262144KB     64bit IO Format:%I64d & %I64u CodeForces 690C1 Description One particularly well-known fact about zombies is that they move and think terribly slowly. While we still don't know…

题目链接: C3. Brain Network (hard) time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Breaking news from zombie neurology! It turns out that – contrary to previous beliefs – every zombie is born …

题目链接: C1. Brain Network (easy) time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output One particularly well-known fact about zombies is that they move and think terribly slowly. While we still do…

C3. Brain Network (hard)   Breaking news from zombie neurology! It turns out that – contrary to previous beliefs – every zombie is born with a single brain, and only later it evolves into a complicated brain structure. In fact, whenever a zombie cons…