树链剖分板子

(n) 个点， (m) 个操作数， 根结点为 (R)， 取模数为 (mod)。

输入一颗树。

支持的操作：

0. 把 (x) 点的点权增加（或修改）(y)。
1. 将树从 (x) 到 (y) 结点最短路径上所有节点的值都加上 (z)。
2. 询问某个节点 (x) 到 (y) 节点的路径中所有点的点权和 (或maxn)。
3. 把 (x) 为根结点的子树中所有点的点权都增加 (y)。
4. 求以 (x) 为根节点的子树内所有节点值之和

const ll N = 3e5 + 4;
ll n, m, tot, R, mod;
ll head[N], fa[N], son[N], siz[N], top[N], dep[N], seg[N], rev[N], a[N], lim[N];

struct nodee
{
    ll to, nxt;
} t[2 * N];

void add(ll x, ll y)
{
    t[++tot].to = y;
    t[tot].nxt = head[x];
    head[x] = tot;
}

void dfs1(ll u, ll father)
{
    siz[u] = 1, fa[u] = father, dep[u] = dep[father] + 1;
    for (ll i = head[u]; i; i = t[i].nxt)
    {
        ll y = t[i].to;
        if (siz[y] == 0)
        {
            dfs1(y, u);
            siz[u] += siz[y];
            if (siz[y] > siz[son[u]])
            {
                son[u] = y;
            }
        }
    }
}

void dfs2(ll u)
{
    seg[u] = ++seg[0];
    rev[seg[0]] = u;
    if (son[u])
    {
        top[son[u]] = top[u];
        dfs2(son[u]);
    }
    for (ll i = head[u]; i; i = t[i].nxt)
    {
        ll y = t[i].to;
        if (y == son[u] || fa[u] == y)
        {
            continue;
        }
        dfs2(y);
    }
    lim[u] = seg[0];
}

struct node
{
    ll L, R, sum, tag, maxn;
    node *lc, *rc;
};

void pushup(node *now)
{
    now->sum = (now->lc->sum + now->rc->sum) % mod;
    now->maxn = max(now->lc->maxn, now->rc->maxn);
}

inline void maketag(node *now, ll w)
{
    now->tag = (now->tag + w) % mod;
    now->sum = (now->sum + (now->R - now->L + 1) * w) % mod;
    now->maxn = w;
}

inline void pushdown(node *now)
{
    if (now->tag == 0)
        return;
    maketag(now->lc, now->tag);
    maketag(now->rc, now->tag);
    now->tag = 0;
}

void build(node *now, ll l, ll r)
{
    now->L = l;
    now->R = r;
    now->tag = 0;
    if (l < r)
    {
        ll mid = (l + r) >> 1;
        now->lc = new node;
        now->rc = new node;
        build(now->lc, l, mid);
        build(now->rc, mid + 1, r);
        pushup(now);
    }
    else
    {
        now->maxn = a[rev[l]];
        now->sum = a[rev[l]];
        now->lc = now->rc = NULL;
    }
}

void change(node *now, ll l, ll r, ll w)
{
    if (l <= now->L and now->R <= r)
    {
        maketag(now, w);
    }
    else if (!((now->L > r) || (now->R < l)))
    {
        pushdown(now);
        change(now->lc, l, r, w);
        change(now->rc, l, r, w);
        pushup(now);
    }
}

ll check1(node *now, ll l, ll r)
{
    if (l <= now->L and now->R <= r)
        return now->sum;
    if ((now->L > r) || (now->R < l))
        return 0;
    pushdown(now);
    return (check1(now->lc, l, r) + check1(now->rc, l, r)) % mod;
}

ll check2(node *now, ll l, ll r)
{
    if (l <= now->L and now->R <= r)
        return now->maxn;
    if ((now->L > r) || (now->R < l))
        return -INF;
    pushdown(now);
    return max(check2(now->lc, l, r), check2(now->rc, l, r));
}

int main()
{
    n = read(), m = read();
    R = 1, mod = INF; // R为根结点序号

    for (ll i = 1; i <= n; i++)
        top[i] = i;

    for (ll i = 1; i <= n; i++)
        a[i] = read();

    for (ll i = 1; i <= n - 1; i++)
    {
        ll x = read(), y = read();
        add(x, y);
        add(y, x);
    }

    dfs1(R, 0);
    dfs2(R);

    node *root;
    root = new node;
    build(root, 1, n);

    for (int i = 1; i <= m; ++i)
    {
        ll opt = read(), x = read(), y, z;

        // 把 x 点的点权增加 y
        // 如果想要修改，更改上面的 maketag
        if (opt == 0) 
        {
            y = read(); 
            change(root, seg[x], seg[x], y);
        }

        // 表示将树从 x 到 y 结点最短路径上所有节点的值都加上 z。
        else if (opt == 1)
        {
            y = read(), z = read();
            while (top[x] != top[y])
            {
                if (dep[top[x]] < dep[top[y]])
                    swap(x, y);
                change(root, seg[top[x]], seg[x], z);
                x = fa[top[x]];
            }
            if(seg[x] > seg[y]) swap(x, y);
            change(root, seg[x], seg[y], z);
        }
        
        // 询问某个节点 x 到 y 节点的路径中所有点的点权和 (或maxn)
        else if (opt == 2)
        {
            y = read();
            ll sum = 0;
            // ll maxn = -2147483647;
            while (top[x] != top[y])
            {
                if (dep[top[x]] < dep[top[y]])
                    swap(x, y);
                sum = (sum + check1(root, seg[top[x]], seg[x])) % mod;
                // maxn = max(maxn, check2(root, seg[top[x]], seg[x]));
                x = fa[top[x]];
            }
            if (seg[x] > seg[y])
                swap(x, y);
            sum = (sum + check1(root, seg[x], seg[y])) % mod;
            // maxn = max(maxn, check2(root, seg[x], seg[y]));
            printf("%lld
", sum);
        }

        // 把 x 为根结点的子树中所有点的点权都增加 y
        else if (opt == 3) 
        {
            y = read();
            change(root, seg[x], lim[x], y);
        }

        // 求以 x 为根节点的子树内所有节点值之和
        else if (opt == 4)
        {
            ll ans = check1(root, seg[x], lim[x]) % mod;
            printf("%lld
", ans);
        }
    }
    return 0;
}