题面
Sol
动态点分治：
建个点分树，每个节点开两颗线段树，以与该点的距离为下标，维护价值和
一棵树维护这个点的，一棵维护对上层重心的贡献
然后。。
然后？直接暴力搞就行了
注意常数优化我TLE了一遍，第二遍卡过去的
# 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[__], sum[__], 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; sum[x] += d;
if(l == r) return;
RG int mid = (l + r) >> 1;
if(pos <= mid) Update(ls[x], l, mid, pos, d);
else Update(rs[x], mid + 1, r, pos, d);
}
IL int Sum(RG int x, RG int l, RG int r, RG int k){
if(!x) return 0;
if(k >= r) return sum[x];
RG int mid = (l + r) >> 1;
if(k > mid) return sum[ls[x]] + Sum(rs[x], mid + 1, r, k);
return Sum(ls[x], l, mid, k);
}
IL void Modify(RG int u, RG int d){
Update(rot[u], 0, n - 1, 0, d);
for(RG int v = u, dis; frt[v]; v = frt[v]){
dis = ChainDiv::Dis(frt[v], u);
Update(rot[frt[v]], 0, n - 1, dis, d);
Update(rot[v + n], 0, n - 1, dis, d);
}
}
IL int Query(RG int u, RG int k){
RG int ans = Sum(rot[u], 0, n - 1, k);
for(RG int v = u, dis; frt[v]; v = frt[v]){
dis = ChainDiv::Dis(frt[v], u);
if(k < dis) continue;
ans += Sum(rot[frt[v]], 0, n - 1, k - dis);
ans -= Sum(rot[v + n], 0, n - 1, k - dis);
}
return ans;
}
int main(RG int argc, RG char* argv[]){
sz = n = Read(); Q = Read(); Fill(fst, -1);
for(RG int i = 1; i <= n; ++i) w[i] = Read();
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(RG int i = 1; i <= n; ++i) Modify(i, w[i]);
for(RG int ans = 0; Q; --Q){
RG int op = Read(), x = Read() ^ ans, y = Read() ^ ans;
if(!op) printf("%d
", ans = Query(x, y));
else Modify(x, y - w[x]), w[x] = y;
}
return 0;
}