37pts，2-10WA了，蒟蒻求调

#include<bits/stdc++.h>
using namespace std;
#define pl p << 1
#define pr p << 1 | 1
const int N = 300010;
int n, m, md, rt, a[N], fa[N], dfn[N], dep[N], cnt, rnk[N], hson[N], sz[N], top[N];
int d[N], lt[N];
vector<int> G[N];
void push_up(int s, int t, int p) {
	d[p] = (d[pl] + d[pr]) % md;
}
void push_down(int s, int t, int p) {
	int m = s + ((t - s) >> 1);
	d[pl] = (d[pl] + (m - s + 1) * lt[p] % md) % md;
	d[pr] = (d[pr] + (t - m) * lt[p] % md) % md;
	lt[pl] = (lt[p] + lt[pl]) % md;
	lt[pr] = (lt[p] + lt[pr]) % md;
	lt[p] = 0;
}
void build(int s, int t, int p) {
	if (s == t) {
		d[p] = a[rnk[s]] % md;
		return ;
	}
	int m = s + ((t - s) >> 1);
	build(s, m, pl);
	build(m + 1, t, pr);
	push_up(s, t, p);
}
void update(int l, int r, int c, int s, int t, int p) {
	if (l <= s && t <= r) {
		d[p] = (d[p] + (t - s + 1) * c % md) % md;
		lt[p] = (lt[p] + c) % md;
		return ;
	}
	int m = s + ((t - s) >> 1);
	if (lt[p]) {
		push_down(s, t, p);
	}
	if (l <= m) {
		update(l, r, c, s, m, pl);
	}
	if (r > m) {
		update(l, r, c, m + 1, t, pr);
	}
	push_up(s, t, p);
}
int query(int l, int r, int s, int t, int p) {
	if (l <= s && t <= r) {
		return d[p];
	}
	int m = s + ((t - s) >> 1);
	if (lt[p]) {
		push_down(s, t, p);
	}
	int ret = 0;
	if (l <= m) {
		ret = (ret + query(l, r, s, m, pl)) % md;
	}
	if (r > m) {
		ret = (ret + query(l, r, m + 1, t, pr)) % md;
	}
	return ret;
}
void dfs1(int x, int f) {
	sz[x] = 1;
	hson[x] = -1;
	fa[x] = f;
	dep[x] = dep[f] + 1;
	for (int i = 0; i < G[x].size(); i++) {
		int y = G[x][i];
		if (y == f)	continue;
		dfs1(y, x);
		sz[x] += sz[y];
		if (i == 0 || sz[y] > sz[hson[x]]) {
			hson[x] = y;
		}
	} 
}
void dfs2(int x, int tp) {
	top[x] = tp;
	dfn[x] = ++cnt;
	rnk[cnt] = x;
	for (int i = 0; i < G[x].size(); i++) {
		int y = G[x][i];
		if (y == fa[x])	continue;
		if (y == hson[x])	dfs2(hson[x], top[x]);
		else	dfs2(y, y);
	}
}
void update_lca(int x, int y, int c) {
	while (top[x] != top[y]) {
		if (dep[top[x]] < dep[top[y]]) {
			swap(x, y);
		}
		update(dfn[top[x]], dfn[x], c, 1, n, 1);
		x = fa[top[x]];
	}
	if (dfn[x] > dfn[y])	swap(x, y);
	update(dfn[x], dfn[y], c, 1, n, 1);
}
int query_lca(int x, int y) {
	int ret = 0;
	while (top[x] != top[y]) {
		if (dep[top[x]] < dep[top[y]]) {
			swap(x, y);
		}
		ret = (ret + query(dfn[top[x]], dfn[x], 1, n, 1)) % md;
		x = fa[top[x]];
	}
	if (dfn[x] > dfn[y])	swap(x, y);
	ret = (ret + query(dfn[x], dfn[y], 1, n, 1)) % md;
	return ret;
}
signed main() {
    scanf("%d%d%d%d", &n, &m, &rt, &md);
    for (int i = 1; i <= n; i++) {
    	scanf("%d", &a[i]);
	}
	for (int i = 1; i < n; i++) {
		int x, y;
		scanf("%d%d", &x, &y);
		G[x].push_back(y);
		G[y].push_back(x);
	}
	dfs1(rt, rt);
	dfs2(rt, rt);
	build(1, n, 1);
	for (int i = 1; i <= m; i++) {
		int op, x, y, z;
		scanf("%d", &op);
		if (op == 1) {
			scanf("%d%d%d", &x, &y, &z);
			z = z % md;
			update_lca(x, y, z);
		}
		if (op == 2) {
			scanf("%d%d", &x, &y);
			cout << query_lca(x, y) << endl;
		}
		if (op == 3) {
			scanf("%d%d", &x, &y);
			y = y % md;
			update(dfn[x], dfn[x] + sz[x] - 1, y, 1, n, 1);
		}	
		if (op == 4) {
			scanf("%d", &x);
			cout << query(dfn[x], dfn[x] + sz[x] - 1, 1, n, 1) << endl;
		}
	}
	return 0;
}