样例过0pts求调（全WA）

#include<bits/stdc++.h>
using namespace std;
#define int long long
const int N=2e5+5; 
int n,m,w[N],a[N],top[N],dep[N],father[N],sz[N],son[N],dfn[N],id[N],cnt;
vector <int> g[N];
struct node{
	int l,r,sum,lazy,maxx,minn;
}tree[4*N];
pair <int,int> bian[N];
void build(int p,int l,int r){
	tree[p]={l,r,0,0,LLONG_MIN,LLONG_MAX};
	if(l==r){
		tree[p].sum=tree[p].maxx=tree[p].minn=a[id[l]];
		return ;
	}
	int mid=l+r>>1;
	build(p<<1,l,mid);build(p<<1|1,mid+1,r);
	tree[p].sum=tree[p<<1].sum+tree[p<<1|1].sum;
	tree[p].maxx=max(tree[p<<1].maxx,tree[p<<1|1].maxx);
	tree[p].minn=min(tree[p<<1].minn,tree[p<<1|1].minn);
}
void pushdown(int p){
	if(tree[p].lazy==0) return ;
	tree[p<<1].lazy^=1;
	tree[p<<1|1].lazy^=1;
	tree[p<<1].sum*=-1;tree[p<<1|1].sum*=-1;
	tree[p<<1].maxx*=-1;tree[p<<1|1].maxx*=-1;
	tree[p<<1].minn*=-1;tree[p<<1|1].minn*=-1;
	swap(tree[p<<1].maxx,tree[p<<1].minn);
	swap(tree[p<<1|1].maxx,tree[p<<1|1].minn);
	tree[p].lazy=0;
} 
void update1(int p,int x,int y,int k){ 
	int l=tree[p].l;
	int r=tree[p].r;
	if(l>=x&&r<=y){
		tree[p].sum=tree[p].maxx=tree[p].minn=k;
		return ;
	}
	pushdown(p);
	int mid=l+r>>1;
	if(x<=mid) update1(p<<1,x,y,k);
	if(y>mid) update1(p<<1|1,x,y,k);
	tree[p].sum=tree[p<<1].sum+tree[p<<1|1].sum;
	tree[p].maxx=max(tree[p<<1].maxx,tree[p<<1|1].maxx);
	tree[p].minn=min(tree[p<<1].minn,tree[p<<1|1].minn);
}
void update2(int p,int x,int y){ 
	int l=tree[p].l;
	int r=tree[p].r;
	if(l>=x&&r<=y){
		tree[p].lazy^=1;
		tree[p].sum*=-1;
		tree[p].maxx*=-1;
		tree[p].minn*=-1;
		swap(tree[p].maxx,tree[p].minn);
		return ;
	}
	pushdown(p);
	int mid=l+r>>1;
	if(x<=mid) update2(p<<1,x,y);
	if(y>mid) update2(p<<1|1,x,y);
	tree[p].sum=tree[p<<1].sum+tree[p<<1|1].sum;
	tree[p].maxx=max(tree[p<<1].maxx,tree[p<<1|1].maxx);
	tree[p].minn=min(tree[p<<1].minn,tree[p<<1|1].minn);
}
int query_sum(int p,int x,int y){
	if(x<=tree[p].l&&tree[p].r<=y) return tree[p].sum;
	pushdown(p);
	int ans=0;
	int mid=tree[p].l+tree[p].r>>1;
	if(x<=mid) ans+=query_sum(p<<1,x,y);
	if(y>mid) ans+=query_sum(p<<1|1,x,y);
	tree[p].sum=tree[p<<1].sum+tree[p<<1|1].sum;
	tree[p].maxx=max(tree[p<<1].maxx,tree[p<<1|1].maxx);
	tree[p].minn=min(tree[p<<1].minn,tree[p<<1|1].minn);
	return ans;
}
int query_max(int p,int x,int y){
	if(x<=tree[p].l&&tree[p].r<=y) return tree[p].maxx;
	pushdown(p);
	int ans=LLONG_MIN;
	int mid=tree[p].l+tree[p].r>>1;
	if(x<=mid) ans=max(ans,query_max(p<<1,x,y));
	if(y>mid) ans=max(ans,query_max(p<<1|1,x,y));
	tree[p].sum=tree[p<<1].sum+tree[p<<1|1].sum;
	tree[p].maxx=max(tree[p<<1].maxx,tree[p<<1|1].maxx);
	tree[p].minn=min(tree[p<<1].minn,tree[p<<1|1].minn);
	return ans;
}
int query_min(int p,int x,int y){
	if(x<=tree[p].l&&tree[p].r<=y) return tree[p].minn;
	pushdown(p);
	int ans=LLONG_MAX;
	int mid=tree[p].l+tree[p].r>>1;
	if(x<=mid) ans=min(ans,query_min(p<<1,x,y));
	if(y>mid) ans=min(ans,query_min(p<<1|1,x,y));
	tree[p].sum=tree[p<<1].sum+tree[p<<1|1].sum;
	tree[p].maxx=max(tree[p<<1].maxx,tree[p<<1|1].maxx);
	tree[p].minn=min(tree[p<<1].minn,tree[p<<1|1].minn);
	return ans;
}
void dfs1(int u,int fa){
	dep[u]=dep[fa]+1,father[u]=fa,sz[u]=1;
	for(auto v:g[u]){
		if(v==fa) continue;
		dfs1(v,u);sz[u]+=sz[v];
		if(sz[v]>sz[son[u]]) son[u]=v;
	}
}
void dfs2(int u,int ftop){
	top[u]=ftop,dfn[++cnt]=u,id[u]=cnt,a[cnt]=w[cnt-1];
	if(son[u]) dfs2(son[u],ftop);
	for(auto v:g[u])
		if(v!=son[u]&&v!=father[u]) dfs2(v,v);
}
void fan(int u,int v){
	while(top[u]!=top[v]){
		if(dep[top[u]]<dep[top[v]]) swap(u,v);
        update2(1,id[top[u]],id[u]);
		u=father[top[u]];
	}
    if(dep[u]>dep[v]) swap(u,v);
    update2(1,id[u],id[v]);
}
void work_sum(int u,int v){
	int ans=0;
	while(top[u]!=top[v]){
		if(dep[top[u]]<dep[top[v]]) swap(u,v);
		ans+=query_sum(1,id[top[u]],id[u]);
		u=father[top[u]];
	}
    if(dep[u]>dep[v]) swap(u,v);
    if(u!=v) ans+=query_sum(1,id[u]+1,id[v]);
    printf("%lld\n",ans);
}
void work_max(int u,int v){
	int ans=LLONG_MIN;
	while(top[u]!=top[v]){
		if(dep[top[u]]<dep[top[v]]) swap(u,v);
		ans=max(ans,query_max(1,id[top[u]],id[u]));
		u=father[top[u]];
	}
    if(dep[u]>dep[v]) swap(u,v);
    if(u!=v) ans=max(ans,query_max(1,id[u]+1,id[v]));
    printf("%lld\n",ans);
}
void work_min(int u,int v){
	int ans=LLONG_MAX;
	while(top[u]!=top[v]){
		if(dep[top[u]]<dep[top[v]]) swap(u,v);
		ans=min(ans,query_min(1,id[top[u]],id[u]));
		u=father[top[u]];
	}
    if(dep[u]>dep[v]) swap(u,v);
    if(u!=v) ans=min(ans,query_min(1,id[u]+1,id[v]));
    printf("%lld\n",ans);
}
signed main(){
    scanf("%lld",&n);
    for(int i=1,u,v,ww;i<n;i++){
    	scanf("%lld%lld%lld",&u,&v,&ww);
        u++,v++;
    	g[u].push_back(v);
    	g[v].push_back(u);
    	w[i]=ww;
    	bian[i]={u,v}; 
	}
    scanf("%lld",&m);
	dfs1(1,0);dfs2(1,1);build(1,1,n);
	while(m--){
		string op;int x,y;
        cin>>op;scanf("%lld%lld",&x,&y);x++,y++; 
		if(op=="C"){
            x--,y--;
			int u=bian[x].first,v=bian[x].second;
			if(dep[u]<dep[v]) swap(u,v);
			update1(1,id[u],id[u],y);
		}
		else if(op=="N") fan(x,y);
		else if(op=="MAX") work_max(x,y);
		else if(op=="MIN") work_min(x,y);
		else work_sum(x,y);
	}
	return 0;
}