rt，昨天打了一遍，今天重新打只有 20pts

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MAXN = 1e5 + 10;
ll n, m, r, p, w[MAXN], a[MAXN], sz[MAXN], Bigson[MAXN], top[MAXN], fa[MAXN], dep[MAXN], id[MAXN], cnt;
vector <int> tr[MAXN];
struct TNode{
	ll val, tag;
}SGT[4*MAXN + 10];
void dfs1(int u, int f){
	dep[u] = dep[f] + 1; 
	fa[u] = f;
	sz[u] = 1;
	int len = tr[u].size();
	for(int i = 0; i < len; i++){
		int v = tr[u][i];
		if(v == f)
			continue;
		dfs1(v, u);
		sz[u] += sz[v];
		if(sz[v] > sz[Bigson[u]])
			Bigson[u] = v; 
	}
}
void dfs2(int u, int h){
	top[u] = h;
	id[u] = ++cnt;
	a[cnt] = w[u];
	if(Bigson[u] == 0)
		return ;
	dfs2(Bigson[u], h);
	int len = tr[u].size();
	for(int i = 0; i < len ; i++){
		int v = tr[u][i];
		if(v == fa[u] || v == Bigson[u])
			continue;
		dfs2(v, v);
	}
}
bool in(int tL, int tR, int l, int r){
	return tL >= l && tR <= r;
}
bool out(int tL, int tR, int l, int r){
	return tL > r || tR < l;
}
void pushup(int u){
	SGT[u].val = SGT[2*u].val + SGT[2*u+1].val;
	SGT[u].val %= p;
}
void makelzy(int u, int len, ll k){
	SGT[u].tag += k;
	SGT[u].val += len * k % p;
	SGT[u].tag %= p, SGT[u].val %= p;
}
void pushdown(int u, int tL, int tR){
	int mid = (tL+tR) / 2;
	makelzy(2*u, mid-tL+1, SGT[u].tag);
	makelzy(2*u+1, tR-mid, SGT[u].tag);
	SGT[u].tag = 0;
}
void build(int u, int tL, int tR){
	if(tL == tR){
		SGT[u].val = a[tL];
		return ;
	}
	int mid = (tL+tR) / 2;
	build(2*u, tL, mid);
	build(2*u+1, mid+1, tR);
	pushup(u);
}
void update(int u, int tL, int tR, int l, int r, ll k){
	if(in(tL, tR, l, r))
		makelzy(u, tL-tR+1, k);
	else if(!out(tL, tR, l, r)){
		pushdown(u, tL, tR);
		int mid = (tL+tR) / 2;
		update(2*u, tL, mid, l, r, k);
		update(2*u+1, mid+1, tR, l, r, k);
		pushup(u);
	}
}
void update_path(int u, int v, ll k){
	while(top[u] != top[v]){
		if(dep[top[u]] < dep[top[v]])
			swap(u, v);
		update(1, 1, n, id[top[u]], id[u], k);
		u = fa[top[u]];
	}
	if(dep[u] < dep[v])
		swap(u, v);
	update(1, 1, n, id[v], id[u], k);
}
ll ask(int u, int tL, int tR, int l, int r){
	if(out(tL, tR, l, r))
		return 0;
	if(in(tL, tR, l, r))
		return SGT[u].val % p;
	pushdown(u, tL, tR);
	int mid = (tL+tR) / 2;
	ll res = ask(2*u, tL, mid, l, r)%p + ask(2*u+1, mid+1, tR, l, r)%p;
	return res % p;
}
ll ask_path(int u, int v){
	ll res = 0; 
	while(top[u] != top[v]){
		if(dep[top[u]] < dep[top[v]])
			swap(u, v);
		res += ask(1, 1, n, id[top[u]], id[u]);
		res %= p;
		u = fa[top[u]];
	}
	if(dep[u] < dep[v])
		swap(u, v);
	res += ask(1, 1, n, id[v], id[u]);
	return res % p;
}
int main(){
	cin >> n >> m >> r >> p;
	for(int i = 1; i <= n; i++)
		cin >> w[i];
	for(int i = 1; i < n; i++){
		int u, v;
		cin >> u >> v;
		tr[u].push_back(v);
		tr[v].push_back(u);
	}
	dfs1(r, 0);
	dfs2(r, r);
	build(1, 1, n);
	while(m--){
		ll op, x, y, z;
		cin >> op;
		switch(op){
			case 1 : {
				cin >> x >> y >> z;
				update_path(x, y, z); 
				break;
			}
			case 2 : {
				cin >> x >> y;
				cout << ask_path(x, y) << endl;
				break;
			}
			case 3 : {
				cin >> x >> z;
				update(1, 1, n, id[x], id[x] + sz[x] - 1, z);
				break;
			}
			case 4 : {
				cin >> x;
				cout << ask(1, 1, n, id[x], id[x]+sz[x] - 1) << endl;
				break;
			}
		}
	}
	return 0;
}