求助，样例过不了

#include <bits/stdc++.h>
using namespace std;
const int MAXN = 100005;
int n, q, r, mod, cnt;
vector<int> G[MAXN];
struct node {
    vector<int> ch;
    int fa, w, dep, siz, son, top, dfn, low;
} a[MAXN];
void dfs1(int u, int fa, int dep) {
    a[u].fa = fa, a[u].dep = dep, a[u].siz = 1;
    for (auto v : G[u]) {
        if (v != fa) {
            a[u].ch.push_back(v);
            dfs1(v, u, dep + 1);
            a[u].siz += a[v].siz;
        }
    }
}
void dfs2(int u, int rt) {
    a[u].dfn = a[u].low = ++cnt, a[u].top = rt;
    for (auto v : a[u].ch) {
        if (a[v].siz > a[a[u].son].siz) a[u].son = v;
    }
    if (!a[u].son) return;
    dfs2(a[u].son, rt);
    for (auto v : a[u].ch) {
        a[u].low = max(a[u].low, a[v].low);
        if (v == a[u].son) continue;
        dfs2(v, v);
    }
}
int c[MAXN * 4], m[MAXN * 4];
inline void pushdown(int l, int r, int mid, int p) {
    if (m[p]) {
        c[p * 2] = (c[p * 2] + (long long)(mid - l + 1) * m[p]) % mod, m[p * 2] = ((long long)m[p * 2] + m[p]) % mod;
        c[p * 2 + 1] = (c[p * 2 + 1] + (long long)(r - mid) * m[p]) % mod, m[p * 2 + 1] = ((long long)m[p * 2 + 1] + m[p]) % mod;
        m[p] = 0;
    }
}
void update(int s, int t, int v, int l, int r, int p) {
    if (s <= l && r <= t) {
        c[p] = (c[p] + (long long)(r - l + 1) * v) % mod, m[p] = ((long long)m[p] + v) % mod;
        return;
    }
    int mid = (l + r) / 2;
    if (l != r) pushdown(l, r, mid, p);
    if (s <= mid) update(s, t, v, l, mid, p * 2);
    if (t > mid) update(s, t, v, mid + 1, r, p * 2 + 1);
    c[p] = ((long long)c[p * 2] + c[p * 2 + 1]) % mod;
}
int getsum(int s, int t, int l, int r, int p) {
    if (s <= l && r <= t) return c[p];
    int mid = (l + r) / 2, ans = 0;
    pushdown(l, r, mid, p);
    if (s <= mid) ans = ((long long)ans + getsum(s, t, l, mid, p * 2)) % mod;
    if (t > mid) ans = ((long long)ans + getsum(s, t, mid + 1, r, p * 2 + 1)) % mod;
    return ans;
}
void upd(int u, int v, int w) {
    while (a[u].top != a[v].top) {
        if (a[a[u].top].dep > a[a[v].top].dep) {
            update(a[a[u].top].dfn, a[u].dfn, w, 1, n, 1);
            u = a[a[u].top].fa;
        } else {
            update(a[a[v].top].dfn, a[v].dfn, w, 1, n, 1);
            v = a[a[v].top].fa;
        }
    }
    if (a[u].dep > a[v].dep) swap(u, v);
    update(a[u].dfn, a[v].dfn, w, 1, n, 1);
}
int qsum(int u, int v) {
    int ans = 0;
    while (a[u].top != a[v].top) {
        if (a[a[u].top].dep > a[a[v].top].dep) {
            ans = ((long long)ans + getsum(a[a[u].top].dfn, a[u].dfn, 1, n, 1)) % mod;
            u = a[a[u].top].fa;
        } else {
            ans = ((long long)ans + getsum(a[a[v].top].dfn, a[v].dfn, 1, n, 1)) % mod;
            v = a[a[v].top].fa;
        }
    }
    if (a[u].dep > a[v].dep) swap(u, v);
    ans = ((long long)ans + getsum(a[u].dfn, a[v].dfn, 1, n, 1)) % mod;
    return ans;
}
inline void updtree(int u, int w) {
    update(a[u].dfn, a[u].low, w, 1, n, 1);
}
inline int qsumtree(int u) {
    return getsum(a[u].dfn, a[u].low, 1, n, 1);
}
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    cin >> n >> q >> r >> mod;
    for (int i = 1; i <= n; i++) cin >> a[i].w;
    for (int i = 1, u, v; i < n; i++) {
        cin >> u >> v;
        G[u].push_back(v), G[v].push_back(u);
    }
    dfs1(r, r, 1);
    dfs2(r, r);
    for (int i = 1; i <= n; i++) update(a[i].dfn, a[i].dfn, a[i].w, 1, n, 1);
    int op, x, y, z;
    while (q--) {
        cin >> op >> x;
        switch (op) {
            case 1:
                cin >> y >> z;
                upd(x, y, z);
                break;
            case 2:
                cin >> y;
                cout << qsum(x, y) << endl;
                break;
            case 3:
                cin >> z;
                updtree(x, z);
                break;
            case 4:
                cout << qsumtree(x) << endl;
                break;
        }
    }
}