Shared code

#include<bits/stdc++.h>
using namespace std;
 
// mx[i] = max distance from i to a leaf from i's subtree 
 
int n, mx[200002], ans[200002];
 
vector<int> v[200002];
 
void dfs(int par, int nod)
{
	for(int i = 0; i < v[nod].size(); ++i)
	{
		int nxt = v[nod][i];
		if(nxt == par)
			continue;
		dfs(nod, nxt);
		mx[nod] = max(mx[nod], mx[nxt] + 1);
	}
}
 
// dist = max dist between nodes that don't belong to the current node's subtree 
void dfs2(int par, int nod, int dist)
{
	ans[nod] = max(mx[nod], dist);
	vector<pair<int, int> >distance;
	for(int i = 0; i < v[nod].size(); ++i)
	{
		int nxt = v[nod][i];
		if(nxt == par)
			continue;
		distance.push_back({mx[nxt] + 1, nxt});
	}
	sort(distance.begin(), distance.end());
	for(int i = 0; i < v[nod].size(); ++i)
	{
		int nxt = v[nod][i];
		if(nxt == par)
			continue;
		if((distance.back()).second == nxt)
		{
			if(distance.size() >= 2)
			{
				int poz = distance.size() - 2;
				dfs2(nod, nxt, max(dist, distance[poz].first) + 1);
			}
			else
				dfs2(nod, nxt, dist + 1);
		}
		else
			dfs2(nod, nxt, max(distance.back().first, dist) + 1);
	}
}
 
int main()
{
	cin >> n;
	for(int i = 1; i < n; ++i)
	{
		int a, b;
		cin >> a >> b;
		v[a].push_back(b);
		v[b].push_back(a);
	}
	dfs(0, 1);
	dfs2(0, 1, 0);
	for(int i = 1; i <= n; ++i)
		cout << ans[i] << " ";
	return 0;
}