求调，感激不尽。

#include<bits/stdc++.h>
#define int long long
#define pb push_back
#define il inline
#define re register
#define pii pair<int,int>
#define fs first
#define sc second
#define md(rt) (tree[rt].l+tree[rt].r>>1)
#define l(rt) (rt<<1)
#define r(rt) (rt<<1|1)
using namespace std;
il int read()
{
	re int x=0;
	re int ff=1;
	re char c=getchar();
	while(c<'0'||c>'9'){
		if(c=='-')
			ff=-1;
		c=getchar();
	}
	while(c>='0'&&c<='9'){
		x=x*10+c-'0';
		c=getchar();
	}
	return x*ff;
}
const int N=3e4+6;
struct edge{
	int v,next;
};
edge e[N<<1];
struct seg_ment{
	int l,r,mx,z;
};
seg_ment tree[N<<2];
int n,f[N],top[N],bh[N],d[N],sz[N],mp[N],son[N],w[N],head[N],k,cnt,q;
il void add(re int u,re int v)
{
	e[++k].v=v;
	e[k].next=head[u];
	head[u]=k;
	return;
}
il void dfs1(re int u,re int fa)
{
	f[u]=fa;
	sz[u]=1;
	d[u]=d[fa]+1;
	for(re int i=head[u];i;i=e[i].next){
		re int v=e[i].v;
		if(v==fa)
			continue;
		dfs1(v,u);
		sz[u]+=sz[v];
		if(sz[son[u]]<sz[v])
			son[u]=v;
	}
	return;
}
il void dfs2(re int u,re int fa)
{
	if(son[u]){
		top[son[u]]=top[u];
		bh[son[u]]=++cnt;
		mp[cnt]=son[u];
		dfs2(son[u],u);
	}
	for(re int i=head[u];i;i=e[i].next){
		re int v=e[i].v;
		if(v==fa||v==son[u])
			continue;
		top[v]=v;
		bh[v]=++cnt;
		mp[cnt]=v;
		dfs2(v,u);
	}
	return;
}
il void push_up(re int rt)
{
	tree[rt].z=tree[l(rt)].z+tree[r(rt)].z;
	tree[rt].mx=max(tree[l(rt)].mx,tree[r(rt)].mx);
	return;
}
il void build(re int rt,re int l,re int r)
{
	tree[rt].l=l;
	tree[rt].r=r;
	if(l==r){
		tree[rt].mx=tree[rt].z=w[mp[l]];
		return;
	}
	int mid=md(rt);
	build(l(rt),l,mid);
	build(r(rt),mid+1,r);
	push_up(rt);
	return;
}
il void updata(re int rt,re int x,re int z)
{
	if(tree[rt].l==tree[rt].r){
		tree[rt].mx=tree[rt].z=z;
		return;
	}
	int mid=md(rt);
	if(x<=mid)
		updata(l(rt),x,z);
	else
		updata(r(rt),x,z);
	push_up(rt);
	return;
}
il int query_sum(re int rt,re int l,re int r)
{
	if(l<=tree[rt].l&&tree[rt].r<=r)
		return tree[rt].z;
	int mid=md(rt),awa=0;
	if(l<=mid)
		awa+=query_sum(l(rt),l,r);
	if(r>mid)
		awa+=query_sum(r(rt),l,r);
	return awa;
}
il int query_mx(re int rt,re int l,re int r)
{
	if(l<=tree[rt].l&&tree[rt].r<=r)
		return tree[rt].mx;
	int mid=md(rt),awa=-1e5;
	if(l<=mid)
		awa=max(awa,query_mx(l(rt),l,r));
	if(r>mid)
		awa=max(awa,query_mx(r(rt),l,r));
	return awa;
}
il int get(re int flag,re int x,re int y)
{
	int awa=(flag?0:-1e5),fx=top[x],fy=top[y];
	while(fx!=fy){
		if(d[fx]>d[fy])
			swap(fx,fy),swap(x,y);
		if(flag)
			awa+=query_sum(1,bh[fy],bh[y]);
		else
			awa=max(awa,query_mx(1,bh[fy],bh[y]));
//		printf("%lld-%lld\n",bh[fy],bh[y]);
		y=f[fy],fy=top[y];
	}
	if(d[x]>d[y])
		swap(x,y);
	if(flag)
		awa+=query_sum(1,bh[x],bh[y]);
	else
		awa=max(awa,query_mx(1,bh[x],bh[y]));
//	printf("%lld-%lld\n",bh[x],bh[y]);
	return awa; 
}
signed main()
{
	n=read();
	for(re int i=1;i<n;i++){
		re int u,v;
		u=read();
		v=read();
		add(u,v);
		add(v,u);
	}
	for(re int i=1;i<=n;i++)
		w[i]=read();
	dfs1(1,0);
	top[1]=1;
	bh[1]=++cnt;
	mp[cnt]=1;
	dfs2(1,0);
	build(1,1,n);
	q=read();
	for(;q;q--){
		char c;
		cin>>c;cin>>c;
		int u,v;
		u=read();
		v=read();
		if(c=='H')
			updata(1,u,v);
		else if(c=='M')
			printf("%lld\n",get(0,u,v));
		else
			printf("%lld\n",get(1,u,v));
	}
	return 0;
}