CSES - Tree Distances I

Solution 1

Described in CPH 14.3.

Solution 2

Compute a diameter of the tree as described by algorithm 2 here. Once we have a diameter $(a,b)$, output $\max (dist(a,i),dist(b,i))$ for each node $i$.

1#include <bits/stdc++.h>
2
3using namespace std;
4
5// dist[0][i] = distance from node a to node i
6// dist[1][i] = distance from node b to node i
7int dist[2][200000];
8vector<int> adj[200000];
9
10int dfs(int u, int p, int d, int i) {