找不出错误……

#include <bits/stdc++.h>
#define int long long
#define min(x, y) (x < y ? x : y)
#define max(x, y) (x > y ? x : y)
#define lowbit(x) (x & -x)
using namespace std;
const int DM[8][2] = {0, 1, 0, -1, 1, 0, -1, 0, 1, 1, 1, -1, -1, 1, -1, -1};
inline void read(int &res)
{
    char ch;
    bool un = 0;
    while (ch = getchar(), !isdigit(ch))
    {
        if (ch == '-')
            un = 1;
    }
    res = ch ^ 48;
    while (ch = getchar(), isdigit(ch))
        res = res * 10 + ch - 48;
    if (un)
    {
        res = -res;
    }
}
const int N = 100001;
vector<int> e[N];
int num[N], seg[N], rev[N], top[N], hvy[N], lst[N], son[N], fa[N], dep[N], p;
void dfs1(int u, int f)
{
    son[u] = 1;
    fa[u] = f;
    dep[u] = dep[f] + 1;
    for (auto v : e[u])
    {
        if (v == f)
        {
            continue;
        }
        dfs1(v, u);
        son[u] += son[v];
        if (son[v] > son[hvy[u]])
        {
            hvy[u] = v;
        }
    }
}
void dfs2(int u, int f)
{
    lst[u] = seg[u];
    if (hvy[u])
    {
        int v = hvy[u];
        seg[v] = ++seg[0];
        rev[seg[0]] = v;
        top[v] = top[u];
        dfs2(v, u);
        lst[u] = max(lst[u], max(seg[v], lst[v]));
    }
    for (auto v : e[u])
    {
        if (top[v] || v == f)
        {
            continue;
        }
        seg[v] = ++seg[0];
        rev[seg[0]] = v;
        top[v] = v;
        dfs2(v, u);
        lst[u] = max(lst[u], max(seg[v], lst[v]));
    }
}
int tree[N * 4 + 5], tag[N * 4 + 5];
void pushup(int k)
{
    tree[k] = (tree[k << 1] + tree[k << 1 | 1]) % p;
}
void addtag(int k, int v)
{
    tag[k] = v;
    tree[k] = (tree[k] + v) % p;
}
void pushdown(int k)
{
    if (!tag[k])
    {
        return;
    }
    addtag(k << 1, tag[k]);
    addtag(k << 1 | 1, tag[k]);
    tag[k] = 0;
}
void build(int k, int l, int r)
{
    if (l == r)
    {
        tree[k] = num[rev[l]];
        return;
    }
    int mid = (l + r) >> 1;
    build(k << 1, l, mid);
    build(k << 1 | 1, mid + 1, r);
    pushup(k);
}
void change(int k, int l, int r, int x, int y, int v)
{
    if (x <= l && r <= y)
    {
        addtag(k, v);
        // tree[k] += v;
        return;
    }
    pushdown(k);
    int mid = (l + r) >> 1;
    if (x <= mid)
    {
        change(k << 1, l, mid, x, y, v);
    }
    if (y > mid)
    {
        change(k << 1 | 1, mid + 1, r, x, y, v);
    }
}
int query(int k, int l, int r, int x, int y)
{
    if (x <= l && r <= y)
    {
        return tree[k];
    }
    pushdown(k);
    int mid = (l + r) >> 1, res = 0;
    if (x <= mid)
    {
        res = (res + query(k << 1, l, mid, x, y)) % p;
    }
    if (y > mid)
    {
        res = (res + query(k << 1 | 1, mid + 1, r, x, y)) % p;
    }
    return res;
}
void trc(int x, int y, int v)
{
    if (top[x] != top[y])
    {
        if (dep[top[x]] < dep[top[y]])
        {
            swap(x, y);
        }
        trc(fa[top[x]], y, v);
        change(1, 1, seg[0], seg[top[x]], seg[x], v);
        return;
    }
    if (dep[x] > dep[y])
    {
        swap(x, y);
    }
    change(1, 1, seg[0], seg[x], seg[y], v);
}
int trq(int x, int y)
{
    if (top[x] != top[y])
    {
        if (dep[top[x]] < dep[top[y]])
        {
            swap(x, y);
        }
        return (trq(fa[top[x]], y) + query(1, 1, seg[0], seg[top[x]], seg[x])) % p;
    }
    if (dep[x] > dep[y])
    {
        swap(x, y);
    }
    return query(1, 1, seg[0], seg[x], seg[y]);
}
signed main()
{
    int n, m, r;
    cin >> n >> m >> r >> p;
    for (int i = 1; i <= n; i++)
    {
        cin >> num[i];
    }
    for (int i = 1; i < n; i++)
    {
        int u, v;
        cin >> u >> v;
        e[u].push_back(v);
        e[v].push_back(u);
    }
    dfs1(r, 0);
    seg[r] = ++seg[0];
    rev[1] = r;
    top[r] = r;
    dfs2(r, 0);
    build(1, 1, n);
    while (m--)
    {
        int opt, x, y, z;
        cin >> opt >> x;
        if (opt == 1)
        {
            cin >> y >> z;
            trc(x, y, z);
        }
        else if (opt == 2)
        {
            cin >> y;
            cout << trq(x, y) << '\n';
        }
        else if (opt == 3)
        {
            cin >> y;
            change(1, 1, n, seg[x], lst[x], y);
        }
        else
        {
            // cout << seg[x] << ' ' << seg[lst[x]] << '\n';
            cout << query(1, 1, n, seg[x], lst[x]) << '\n';
        }
    }
    return 0;
}