rt，题解和讨论区的 hack 均过了，拍也拍不出来，求大佬调。

#include <bits/stdc++.h>
#define ls p<<1
#define rs p<<1|1
#define fi first
#define se second
#define pb push_back
#define mk make_pair
#define ll long long
#define space putchar(' ')
#define enter putchar('\n')
using namespace std;

inline int read() {
	int x = 0, f = 1;
	char c = getchar();
	while (c < '0' || c > '9') f = c == '-' ? -1 : f, c = getchar();
	while (c >= '0' && c <= '9') x = (x<<3)+(x<<1)+(c^48), c = getchar();
	return x*f;
}

inline void write(int x) {
	if (x < 0) x = -x, putchar('-');
	if (x > 9) write(x/10);
	putchar('0'+x%10);
}

const int N = 1e5+5, inf = 1e9;
struct seg {
	int sum, res, lmx, rmx, col, len;
	seg(int sum = 0, int res = 0, int lmx = 0, int rmx = 0, int col = 0, int len = 0):sum(sum), res(res), lmx(lmx), rmx(rmx), col(col), len(len) {}
} t[N<<2];
int n, m, idx, a[N], d[N], fa[N], id[N], to[N], siz[N], son[N], top[N];
vector <int> E[N];

void dfs1(int x, int f) {
	d[x] = d[f]+1, fa[x] = f, siz[x] = 1; int mx = 0;
	for (int y:E[x]) if (y != f) {
		dfs1(y, x);
		siz[x] += siz[y];
		if (siz[y] > mx) son[x] = y, mx = siz[y];
	}
}

void dfs2(int x, int topf) {
	id[x] = ++idx, to[idx] = x, top[x] = topf;
	if (!son[x]) return;
	dfs2(son[x], topf);
	for (int y:E[x]) if (y != fa[x] && y != son[x]) dfs2(y, y);
}

void pushup(int p) {
	t[p].sum = t[ls].sum+t[rs].sum;
	t[p].lmx = max(t[ls].lmx, t[ls].sum+t[rs].lmx);
	t[p].rmx = max(t[rs].rmx, t[rs].sum+t[ls].rmx);
	t[p].res = max(max(t[ls].res, t[rs].res), t[ls].rmx+t[rs].lmx);
}

void pushdown(int p) {
	if (t[p].col == inf) return;
	t[ls].sum = t[p].col*t[ls].len;
	t[rs].sum = t[p].col*t[rs].len;
	t[ls].res = t[ls].lmx = t[ls].rmx = max(0, t[ls].sum);
	t[rs].res = t[rs].lmx = t[rs].rmx = max(0, t[rs].sum);
	t[ls].col = t[rs].col = t[p].col;
	t[p].col = inf;
}

void build(int p, int l, int r) {
	t[p].col = inf, t[p].len = r-l+1;
	if (l == r) {
		t[p].sum = a[to[l]];
		t[p].res = t[p].lmx = t[p].rmx = max(0, a[to[l]]);
		return;
	}
	int mid = l+r>>1;
	build(ls, l, mid), build(rs, mid+1, r);
	pushup(p);
}

void upd(int p, int l, int r, int ql, int qr, int x) {
	if (qr < l || r < ql) return;
	if (ql <= l && r <= qr) {
		t[p].sum = x*t[p].len;
		t[p].res = t[p].lmx = t[p].rmx = max(0, t[p].sum);
		t[p].col = x;
		return;
	}
	pushdown(p); int mid = l+r>>1;
	upd(ls, l, mid, ql, qr, x), upd(rs, mid+1, r, ql, qr, x);
	pushup(p);
}

seg que(int p, int l, int r, int ql, int qr) {
	if (ql <= l && r <= qr) return t[p];
	pushdown(p); int mid = l+r>>1;
	if (qr <= mid) return que(ls, l, mid, ql, qr);
	if (mid < ql) return que(rs, mid+1, r, ql, qr);
	seg x = que(ls, l, mid, ql, qr), y = que(rs, mid+1, r, ql, qr), res;
	res.sum = x.sum+y.sum;
	res.lmx = max(x.lmx, x.sum+y.lmx);
	res.rmx = max(y.rmx, y.sum+x.rmx);
	res.res = max(max(x.res, y.res), x.rmx+y.lmx);
	return res;
}

void modify(int x, int y, int k) {
	while (top[x] != top[y]) {
		if (d[top[x]] < d[top[y]]) swap(x, y);
		upd(1, 1, n, id[top[x]], id[x], k);
		x = fa[top[x]];
	}
	if (d[x] > d[y]) swap(x, y);
	upd(1, 1, n, id[x], id[y], k);
}

int solve(int x, int y) {
	seg l, r;
	while (top[x] != top[y]) {
		if (d[top[x]] < d[top[y]]) swap(x, y), swap(l, r);
		seg k = que(1, 1, n, id[top[x]], id[x]), res;
		res.sum = l.sum+k.sum;
		res.lmx = max(l.lmx, l.sum+k.rmx);
		res.rmx = max(k.lmx, k.sum+l.rmx);
		res.res = max(max(l.res, k.res), l.rmx+k.rmx);
		l = res;
		x = fa[top[x]];
	}
	if (d[x] > d[y]) swap(x, y), swap(l, r);
	seg k = que(1, 1, n, id[x], id[y]), res;
	res.sum = l.sum+k.sum;
	res.lmx = max(l.lmx, l.sum+k.rmx);
	res.rmx = max(k.lmx, k.sum+l.rmx);
	res.res = max(max(l.res, k.res), l.rmx+k.rmx);
	l = res;
	return max(max(l.res, r.res), l.rmx+r.rmx);
}

void print(int p, int l, int r) {
	printf("%d:[%d,%d]:\nsum:%dres:%dlmx:%drmx:%d\n", p, l, r, t[p].sum, t[p].res, t[p].lmx, t[p].rmx);
	if (l == r) return;
	int mid = l+r>>1;
	print(ls, l, mid), print(rs, mid+1, r);
}

int main() {
	n = read();
	for (int i = 1; i <= n; ++i) a[i] = read();
	for (int i = 1; i < n; ++i) {
		int x = read(), y = read();
		E[x].pb(y), E[y].pb(x);
	}
	dfs1(1, 0), dfs2(1, 1), build(1, 1, n);
	//for (int i = 1; i <= n; ++i) printf("%d ", top[i]); enter;
	//print(1, 1, n);
	m = read();
	while (m--) {
		int op = read(), x = read(), y = read(), k;
		if (op == 1) write(solve(x, y)), enter;
		else k = read(), modify(x, y, k);
	}
	return 0;
}