树剖裸题
#include <iostream>
#include <cstdio>
using namespace std;
int n, uu, vv, hea[30005], ecnt, w[30005], ww[30005], dep[30005], cnt;
int idx[30005], son[30005], fa[30005], top[30005], q, wt[30005], siz[30005];
char ss[15];
struct Edge{
int too, nxt;
}edge[60005];
void add_edge(int fro, int too){
edge[++ecnt].nxt = hea[fro];
edge[ecnt].too = too;
hea[fro] = ecnt;
}
struct SGT{
int sum[120005];
int zdz[120005];
void build(int o, int l, int r){
if(l==r) zdz[o] = sum[o] = wt[l];
else{
int mid=(l+r)>>1;
int lson=o<<1;
int rson=lson|1;
zdz[lson] = zdz[rson] = -0x3f3f3f3f;
if(l<=mid) build(lson, l, mid);
if(mid<r) build(rson, mid+1, r);
sum[o] = sum[lson] + sum[rson];
zdz[o] = max(zdz[lson], zdz[rson]);
}
}
void change(int o, int l, int r, int x, int k){
if(l>=x && r<=x) sum[o] = zdz[o] = k;
else{
int mid=(l+r)>>1;
int lson=o<<1;
int rson=lson|1;
if(x<=mid) change(lson, l, mid, x, k);
if(mid<x) change(rson, mid+1, r, x, k);
sum[o] = sum[lson] + sum[rson];
zdz[o] = max(zdz[lson], zdz[rson]);
}
}
int querySum(int o, int l, int r, int x, int y){
if(l>=x && r<=y) return sum[o];
else{
int mid=(l+r)>>1;
int lson=o<<1;
int rson=lson|1;
int ans=0;
if(x<=mid) ans += querySum(lson, l, mid, x, y);
if(mid<y) ans += querySum(rson, mid+1, r, x, y);
return ans;
}
}
int queryZdz(int o, int l, int r, int x, int y){
if(l>=x && r<=y) return zdz[o];
else{
int mid=(l+r)>>1;
int lson=o<<1;
int rson=lson|1;
int ans=-0x3f3f3f3f;
if(x<=mid) ans = max(ans, queryZdz(lson, l, mid, x, y));
if(mid<y) ans = max(ans, queryZdz(rson, mid+1, r, x, y));
return ans;
}
}
}sgt;
void dfs1(int x, int f){
fa[x] = f;
dep[x] = dep[f] + 1;
siz[x] = 1;
int maxSon=-1;
for(int i=hea[x]; i; i=edge[i].nxt){
int t=edge[i].too;
if(t==f) continue;
dfs1(t, x);
siz[x] += siz[t];
if(maxSon<siz[t]){
maxSon = siz[t];
son[x] = t;
}
}
}
void dfs2(int x, int topf){
top[x] = topf;
idx[x] = ++cnt;
wt[cnt] = w[x];
if(!son[x]) return ;
dfs2(son[x], topf);
for(int i=hea[x]; i; i=edge[i].nxt){
int t=edge[i].too;
if(t==fa[x] || t==son[x]) continue;
dfs2(t, t);
}
}
int queryRangeSum(int uu, int vv){
int ans=0;
while(top[uu]!=top[vv]){
if(dep[top[uu]]<dep[top[vv]]) swap(uu, vv);
ans += sgt.querySum(1, 1, n, idx[top[uu]], idx[uu]);
uu = fa[top[uu]];
}
if(dep[uu]>dep[vv]) swap(uu, vv);
ans += sgt.querySum(1, 1, n, idx[uu], idx[vv]);
return ans;
}
int queryRangeZdz(int uu, int vv){
int ans=-0x3f3f3f3f;
while(top[uu]!=top[vv]){
if(dep[top[uu]]<dep[top[vv]]) swap(uu, vv);
ans = max(ans, sgt.queryZdz(1, 1, n, idx[top[uu]], idx[uu]));
uu = fa[top[uu]];
}
if(dep[uu]>dep[vv]) swap(uu, vv);
ans = max(ans, sgt.queryZdz(1, 1, n, idx[uu], idx[vv]));
return ans;
}
int main(){
cin>>n;
for(int i=1; i<n; i++){
scanf("%d %d", &uu, &vv);
add_edge(uu, vv);
add_edge(vv, uu);
}
for(int i=1; i<=n; i++)
scanf("%d", &w[i]);
dep[1] = 1;
dfs1(1, 0);
dfs2(1, 1);
sgt.build(1, 1, n);
cin>>q;
while(q--){
scanf("%s %d %d", ss, &uu, &vv);
if(ss[1]=='H') sgt.change(1, 1, n, idx[uu], vv);
if(ss[1]=='M') printf("%d
", queryRangeZdz(uu, vv));
if(ss[1]=='S') printf("%d
", queryRangeSum(uu, vv));
}
return 0;
}