JOI 2013 - Synchronization

Method 1 - ?

When deleting an edge, remember how many systems that edge was used to synchronize. Also, each moment there is a connected component, all computers in the component have the same value.

Andi Qu

^ This is $\mathcal{O}(N\log^2N)$ I think

If we use HLD or LCT then it's $\mathcal{O}(N\log N)$.

Method 2 - Centroid Decomposition

Looks like $\mathcal{O}(N \log^3 N)$ is very fast!

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#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using ld = long double;
using db = double;
using str = string;  // yay python!

using pi = pair<int, int>;
using pl = pair<ll, ll>;