题面

戳我

Sol

和bzoj震波那道题差不多
加上线段树标记永久化就好了

# include <bits/stdc++.h>
# define RG register
# define IL inline
# define Fill(a, b) memset(a, b, sizeof(a))
using namespace std;
typedef long long ll;
const int _(2e5 + 10), __(2e7 + 10);

IL ll Read(){
    RG ll x = 0, z = 1; RG char c = getchar();
    for(; c < '0' || c > '9'; c = getchar()) z = c == '-' ? -1 : 1;
    for(; c >= '0' && c <= '9'; c = getchar()) x = (x << 1) + (x << 3) + (c ^ 48);
    return x * z;
}

int n, fst[_], nxt[_], w[_], to[_], cnt, Q;

IL void Add(RG int u, RG int v){  nxt[cnt] = fst[u]; to[cnt] = v; fst[u] = cnt++;  }

namespace ChainDiv{
    int fa[_], size[_], top[_], deep[_], son[_], dfn[_], Index;

    IL void Dfs1(RG int u){
        size[u] = 1;
        for(RG int e = fst[u]; e != -1; e = nxt[e]){
            if(size[to[e]]) continue;
            deep[to[e]] = deep[u] + 1; fa[to[e]] = u;
            Dfs1(to[e]);
            size[u] += size[to[e]];
            if(size[to[e]] > size[son[u]]) son[u] = to[e];
        }
    }

    IL void Dfs2(RG int u, RG int Top){
        top[u] = Top; dfn[u] = ++Index;
        if(son[u]) Dfs2(son[u], Top);
        for(RG int e = fst[u]; e != -1; e = nxt[e]) if(!dfn[to[e]]) Dfs2(to[e], to[e]);
    }

    IL ll Dis(RG int u, RG int v){
        RG ll dis = deep[u] + deep[v];
        while(top[u] ^ top[v]){  if(deep[top[u]] < deep[top[v]]) swap(u, v); u = fa[top[u]];  }
        if(deep[u] > deep[v]) swap(u, v);
        return dis - 2 * deep[u];
    }
}

int rot[_], ls[__], rs[__], tag[__], tot;
int size[_], mx[_], frt[_], vis[_], rt, sz, root;

IL void Getroot(RG int u, RG int ff){
    size[u] = 1; mx[u] = 0;
    for(RG int e = fst[u]; e != -1; e = nxt[e]){
        if(vis[to[e]] || to[e] == ff) continue;
        Getroot(to[e], u);
        size[u] += size[to[e]];
        mx[u] = max(mx[u], size[to[e]]);
    }
    mx[u] = max(mx[u], sz - size[u]);
    if(mx[u] < mx[rt]) rt = u;
}

IL void Create(RG int u, RG int ff){
    frt[u] = ff; vis[u] = 1;
    for(RG int e = fst[u]; e != -1; e = nxt[e]){
        if(vis[to[e]]) continue;
        rt = 0; sz = size[to[e]];
        Getroot(to[e], u); Create(rt, u);
    }
}

IL void Update(RG int &x, RG int l, RG int r, RG int pos, RG int d){
    if(!x) x = ++tot;
    if(pos >= r){  tag[x] += d; return;  }
    RG int mid = (l + r) >> 1;
    if(pos > mid) Update(rs[x], mid + 1, r, pos, d);
    Update(ls[x], l, mid, pos, d);
}

IL int Sum(RG int x, RG int add, RG int l, RG int r, RG int k){
    if(!x) return add; add += tag[x];
    if(l == r) return add;
    RG int mid = (l + r) >> 1;
    if(k <= mid) return Sum(ls[x], add, l, mid, k);
    return Sum(rs[x], add, mid + 1, r, k);
}

IL void Modify(RG int u, RG int k, RG int d){
    Update(rot[u], 0, n - 1, k, d);
    for(RG int v = u, dis; frt[v]; v = frt[v]){
        dis = ChainDiv::Dis(frt[v], u);
        if(k < dis) continue;
        Update(rot[frt[v]], 0, n - 1, k - dis, d);
        Update(rot[v + n], 0, n - 1, k - dis, d);
    }
}

IL int Query(RG int u){
    RG int ans = Sum(rot[u], 0, 0, n - 1, 0);
    for(RG int v = u, dis; frt[v]; v = frt[v]){
        dis = ChainDiv::Dis(frt[v], u);
        ans += Sum(rot[frt[v]], 0, 0, n - 1, dis);
        ans -= Sum(rot[v + n], 0, 0, n - 1, dis);
    }
    return ans;
}

int main(RG int argc, RG char* argv[]){
    sz = n = Read(); Q = Read(); Fill(fst, -1);
    for(RG int i = 1, a, b; i < n; ++i) a = Read(), b = Read(), Add(a, b), Add(b, a);
    ChainDiv::Dfs1(1); ChainDiv::Dfs2(1, 1);
    mx[0] = n + 1; cnt = 0;
    Getroot(1, 0); root = rt; Create(rt, 0);
    for(; Q; --Q){
        RG char op; scanf(" %c", &op); RG int x = Read(), y, z;
        if(op == 'Q') printf("%d\n", Query(x));
        else y = Read(), z = Read(), Modify(x, y, z);
    }
    return 0;
}