只能过第一个点。码风优良，求调十分感谢。

#include <bits/stdc++.h>

using namespace std;
#define ls u<<1
#define rs u<<1|1
const int N = 1e5 + 5;
int n, m;
int rt;
vector<int>e[N];
int w[N];
int id[N], nw[N], cnt;
int fa[N], son[N], siz[N], top[N], dep[N];

void dfs1(int u, int f)
{
	siz[u] = 1;
	dep[u] = dep[f] + 1;
	fa[u] = f;
	for (int v : e[u]) {
		if (v == f) continue;
		dfs1(v, u);
		siz[u] += siz[v];
		if (siz[son[u]] < siz[v]) son[u] = v;
	}
}
void dfs2(int u, int t)
{
	top[u] = t; id[u] = ++cnt; nw[cnt] = w[u];
	if (!son[u]) return;
	dfs2(son[u], t);
	for (int v : e[u]) {
		if (v == son[u] || v == fa[u]) continue;
		dfs2(v, v);
	}
}

struct Segm{
	int l, r, minv, tag;
	Segm() {minv = 1e9; tag = 0;}
} tree[N << 2];

inline void pushup(int u) {tree[u].minv = min(tree[ls].minv, tree[rs].minv); }
inline void pushdown(int u)
{
	if (tree[u].tag) {
		tree[ls].minv = tree[rs].minv = tree[u].tag;
		tree[ls].tag = tree[rs].tag = tree[u].tag;
		tree[u].tag = 0;
	}
}

void build(int u, int l, int r)
{
	tree[u].l = l, tree[u].r = r;
	if (l == r) {
		tree[u].minv = nw[l]; // mention
		return ;
	}
	int mid = l + r >> 1;
	build(ls, l, mid);
	build(rs, mid + 1, r);
	pushup(u);
}
void qqq(int u, int l, int r)
{
	if (l == r) {
		cout << tree[u].minv << " ";
		return ;
	}
	int mid = l + r >> 1;
	qqq(ls, l, mid);
	qqq(rs, mid + 1, r);
}

void modify(int u, int l, int r, int val)
{
	if (l <= tree[u].l && tree[u].r <= r) {
		tree[u].minv = val;
		tree[u].tag = val;
		return;
	}
	pushdown(u);
	int mid = tree[u].l + tree[u].r >> 1;
	if (mid >= l) modify(ls, l, r, val);
	if (mid < r) modify(rs, l, r, val);
	pushup(u);
}

int query(int u, int l, int r)
{
	if (l <= tree[u].l && tree[u].r <= r) {
		return tree[u].minv;
	}
	pushdown(u);
	int ans = 1e9;
	int mid = tree[u].l + tree[u].r >> 1;
	if (mid >= l) ans = min(ans, query(ls, l, r));
	if (mid < r) ans = min(ans, query(rs, l, r));
	return ans;
}

int lca(int u, int v)
{
	while (top[u] != top[v]) {
		if (dep[top[u]] < dep[top[v]]) swap(u, v);
		u = fa[top[u]];
	}
	return dep[u] < dep[v] ? u : v;
}

void modify_sect(int u, int v, int val)
{
	while (top[u] != top[v]) {
		if (dep[top[u]] < dep[top[v]]) swap(u, v);
		modify(1, id[top[u]], id[u], val);
		u = fa[top[u]];
	}
	if (dep[u] < dep[v]) swap(u, v);
	modify(1, id[v], id[u], val);
}

int query_subtree(int u)
{
	if (u == rt) {
		return tree[1].minv; // mention
	} else if (dep[u] < dep[rt] && lca(u, rt) == u) {
		return min(query(1, 1, id[rt] - 1), query(1, id[rt] + siz[rt], n)); // wrong
	} else {
		return query(1, id[u], id[u] + siz[u] - 1);
	}
}

int main()
{
	scanf("%d%d", &n, &m);
	for (int i = 1, u, v; i < n; i++) {
		scanf("%d%d", &u, &v);
		e[u].push_back(v);
		e[v].push_back(u);
	}
	for (int i = 1; i <= n; i++) {
		scanf("%d", &w[i]);
	}
	scanf("%d", &rt);
	dfs1(rt, 0);
	dfs2(rt, rt);
	build(1, 1, n);
	// cout << query(1, 1, 1) << " " << query(1, 2, 2) << " " << query(1, 3, 3) << endl;
	for (int i = 1, op, u, v, w; i <= m; i++) {
		scanf("%d", &op);
		if (op == 1) {
			scanf("%d", &rt);
		} else if (op == 2) {
			scanf("%d%d%d", &u, &v, &w);
			modify_sect(u, v, w);
		} else {
			scanf("%d", &u);
			printf("%d\n", query_subtree(u));
		}
	}
	return 0;
}