第三次了。。。

#include <bits/stdc++.h> 
using namespace std;
int n, m, k;
int f[100005][16], dep[100005];
int ans[100005];
vector <int> G[100005];
queue <pair <int, int> > q;
set <int> s1, s2;
struct Query {int x, y;}a[100005];
void dfs (int u) {
	for (int i = 1; i <= 15; i ++) f[u][i] = f[f[u][i - 1] ][i - 1];
	for (int v : G[u]) {
		if (v == f[u][0]) continue;
		f[v][0] = u;
		dep[v] = dep[u] + 1;
		dfs (v);
	}
}
int lca (int x, int y) {
	if (dep[x] < dep[y]) swap (x, y);
	for (int i = 15; i >= 0; i --) if (dep[f[x][i] ] >= dep[y]) x = f[x][i];
	if (x == y) return x;
	for (int i = 15; i >= 0; i --) if (f[x][i] != f[y][i]) {
		x = f[x][i];
		y = f[y][i];
	}
	return f[x][0];
}
int dis (int x, int y) {return dep[x] + dep[y] - 2 * dep[lca (x, y)];}
int main () {
	dep[1] = 1;
	cin >> n;
	for (int i = 1; i < n; i ++) {
		int u, v;
		cin >> u >> v;
		G[u].push_back (v);
		G[v].push_back (u);
	}
	dfs (1);
	cin >> m;
	for (int i = 1; i <= m; i ++) cin >> a[i].x >> a[i].y;
	for (int i = 1; i <= m; i += 300) {
		s1.clear ();
		s2.clear ();
		k = 0;
		for (int j = 1; j <= n; j ++) ans[j] = 1000000000;
		for (int j = 1; j < i; j ++) if (a[j].x == 0) {
			if (s1.find (a[j].y) != s1.end () ) s1.erase (a[j].y);
			else s1.insert (a[j].y);
		}
		for (int it : s1) {
			q.push (make_pair (it, 0) );
			ans[it] = 0;
		}
		while (!q.empty () ) {
			int u = q.front ().first, dis = q.front ().second;
			q.pop ();
			for (int v : G[u]) {
				if (ans[v] != 1000000000) continue;
				ans[v] = dis + 1;
				q.push (make_pair (v, ans[v]) );
			}
		}
		for (int j = i; j < i + 300 && j <= m; j ++) {
			if (a[j].x == 0) {
				if (s2.find (a[j].y) != s2.end () ) s2.erase (a[j].y);
				else s2.insert (a[j].y);
			}
			else {
				for (int it : s2)
					ans[a[j].y] = min (ans[a[j].y], dis (a[j].y, it) );
				cout << (ans[a[j].y] == 1000000000 ? -1 : ans[a[j].y])<< "\n";
			}
		}
	}
	return 0;
}