方法很简单，树剖，把区间提取出来，打翻转标记，再放回去。本来以为写起来也很简单T_T

注：由于某种原因，我写的是把题目中的r忽略掉的一般情况，否则写起来简单得多。

#include
     
      #define N 50005#define M (s+t>>1)#define L(t)(t)->c[0]#define R(t)(t)->c[1]#define Z(t)(L(t)->s+1)using namespace std;typedef long long ll;struct edge{	int v;	edge*s;}e[N*2];edge*back=e,*h[N];void add(int u,int v){	*back={v,h[u]};	h[u]=back++;	*back={u,h[v]};	h[v]=back++;}typedef int arr[N];arr d,p,num,size,son,top;void dfs1(int u){	d[u]=d[p[u]]+1;	size[u]=1;	int s=0;	for(edge*i=h[u];i;i=i->s)		if(i->v!=p[u]){			p[i->v]=u;			dfs1(i->v);			size[u]+=size[i->v];			if(s
      
       v])				s=size[son[u]=i->v];		}}void dfs2(int u){	static int tot;	num[u]=++tot;	if(size[u]!=1){		top[son[u]]=top[u];		dfs2(son[u]);	}	for(edge*i=h[u];i;i=i->s)		if(i->v!=p[u]&&i->v!=son[u])			dfs2(top[i->v]=i->v);}struct node{	ll a[3];	int s,u,v;	bool rev;	node*c[2];}mem[N];node*last=mem,null[1]={0,1<<30},*root;ll Sum(ll u,ll v){	return u+v;}ll Min(ll u,ll v){	return u
       
        rev){		L(t)->rev^=1;		R(t)->rev^=1;		t->rev=0;		swap(L(t),R(t));	}	if(int u=t->u){		t->u=0;		L(t)->u+=u;		R(t)->u+=u;		t->a[1]+=u;		t->a[2]+=u;		t->v+=u;		t->a[0]+=u*t->s;	}	return Z(t);}node*update(node*t){	devolve(L(t));	devolve(R(t));	for(int i=0;i!=3;++i)		t->a[i]=f[i](f[i](L(t)->a[i],R(t)->a[i]),t->v);	t->s=R(t)->s+Z(t);	return t;}void link(bool i,node*&t,node*&s){	node*d=t->c[i];	t->c[i]=s;	s=update(t),t=d;}node*splay(int v,node*&t=root){	node*d[]={		null,null	};	while(v!=devolve(t)){		bool i=v>Z(t);		v-=i*Z(t);		if(v!=devolve(t->c[i])&&i==v>Z(t->c[i])){			v-=i*Z(t->c[i]);			link(i,t,t->c[i]->c[i^1]);		}		link(i,t,d[i]);	}	for(int i=0;i!=2;++i){		node*s=t->c[i^1];		while(d[i]!=null)			link(i,d[i],s);		t->c[i^1]=s;	}	return update(t);}node*&splay(int s,int t){	splay(s);	return L(splay(t-s+2,R(root)));}node*build(int s,int t){	if(s<=t){		node*i=last++;		L(i)=build(s,M-1);		R(i)=build(M+1,t);		return update(i);	}	return null;}struct vec{	int u,v,a;	vec(){}	vec(int u,int v):u(u),v(v),a(u){}	int size(){		return v-u+1;	}}u[N],v[N];int solve(int i,int j,vec*&u,vec*&v){	vec**s=&u,**t=&v;	for(;top[i]!=top[j];i=p[top[i]]){		if(d[top[i]]
        
         u,s->v)->u+=j;	while(t--!=v)		splay(t->u,t->v)->u+=j;}ll query(int p,int q,int i){	ll j=i^1?0:1<<30;	vec*s=u,*t=v;	solve(p,q,s,t);	while(s--!=u)		j=f[i](j,splay(s->u,s->v)->a[i]);	while(t--!=v)		j=f[i](j,splay(t->u,t->v)->a[i]);	return j;}void invert(int p,int q){	node*j=null;	vec*s=u,*t=v;	solve(p,q,s,t);	vec*e=s;	while(t--!=v)		*e++=*t;	for(vec*i=u;i!=e;++i){		node*&a=splay(i->u,i->v);		a->rev=i
         
          a
          
           a){ z->u-=i->size(); z->v-=i->size(); } } j->rev=1; for(vec*i=u;i!=e;++i){ node*&a=splay(i->u,i->u-1); a=j; j=R(splay(i->size(),a)); a->rev=i
           
            a
            
             a){ z->u+=i->size(); z->v+=i->size(); } }}int main(){ int n,m,s,t,u; char a[10]; scanf("%d%d%*d",&n,&m); root=build(0,n+1); for(int i=1;i!=n;++i){ scanf("%d%d",&s,&t); add(s,t); } dfs1(1); dfs2(top[1]=1); while(m--){ scanf("%s%d%d",a,&s,&t); if(a[2]=='v') invert(s,t); else if(a[2]=='c'){ scanf("%d",&u); amend(s,t,u); }else printf("%lld\n",query(s,t,a[2]=='j'?2:a[2]!='m')); }}