#include using namespace std; using ll=long long; using ull=unsigned long long; using P=pair; templateusing minque=priority_queue,greater>; templatebool chmax(T &a,const T &b){return (abool chmin(T &a,const T &b){return (a>b?(a=b,true):false);} templateistream &operator>>(istream &is,pair&p){is>>p.first>>p.second;return is;} templateistream &operator>>(istream &is,tuple&a){is>>std::get<0>(a)>>std::get<1>(a)>>std::get<2>(a);return is;} templateistream &operator>>(istream &is,array&a){for(auto&i:a)is>>i;return is;} templateistream &operator>>(istream &is,vector &a){for(auto &i:a)is>>i;return is;} templatevoid operator++(pair&a,int n){a.first++,a.second++;} templatevoid operator--(pair&a,int n){a.first--,a.second--;} templatevoid operator++(vector&a,int n){for(auto &i:a)i++;} templatevoid operator--(vector&a,int n){for(auto &i:a)i--;} #define overload3(_1,_2,_3,name,...) name #define rep1(i,n) for(int i=0;i<(int)(n);i++) #define rep2(i,l,r) for(int i=(int)(l);i<(int)(r);i++) #define rep(...) overload3(__VA_ARGS__,rep2,rep1)(__VA_ARGS__) #define reps(i,l,r) rep2(i,l,r) #define all(x) x.begin(),x.end() #define pcnt(x) __builtin_popcountll(x) #define fin(x) return cout<<(x)<<'\n',static_cast(0) #define yn(x) cout<<((x)?"Yes\n":"No\n") #define uniq(x) sort(all(x)),x.erase(unique(all(x)),x.end()) template inline int fkey(vector&z,T key){return lower_bound(z.begin(),z.end(),key)-z.begin();} ll myceil(ll a,ll b){return (a+b-1)/b;} template auto vec(const int (&d)[n],const T &init=T()){ if constexpr (id(d,init)); else return init; } #ifdef LOCAL #include #define SWITCH(a,b) (a) #else #define debug(...) static_cast(0) #define debugg(...) static_cast(0) #define SWITCH(a,b) (b) templateostream &operator<<(ostream &os,const pair&p){os<>testcase; for(int i=0;i struct Edge{ int from,to; T weight; int index; Edge(int from_,int to_,T weight_=T(),int index_=-1):from(from_),to(to_),weight(weight_),index(index_){} Edge():from(-1),to(-1),weight(),index(-1){} friend std::ostream &operator<<(std::ostream &os,const Edge&e){ os<<'['; os<<"from:"< struct Tree{ int n,r; std::vector>edge; std::vector>g; std::vectorptr; struct tree_range{ using iterator=typename std::vector>::iterator; iterator l,r; iterator begin()const{return l;} iterator end()const{return r;} int size()const{return r-l;} bool empty()const{return !size();} Edge &operator[](int i)const{return l[i];} }; struct const_tree_range{ using iterator=typename std::vector>::const_iterator; iterator l,r; iterator begin()const{return l;} iterator end()const{return r;} int size()const{return r-l;} bool empty()const{return !size();} const Edge &operator[](int i)const{return l[i];} }; explicit Tree(int n_):n(n_){ edge.reserve(n-1); } Tree():n(0){} Tree(int n_,const std::vector>&e,bool dir=false):n(n_),r(-1),edge(e){ if(!dir)build(); else{ std::vectorseen(n,false); ptr.resize(n+1); for(const Edge&i:edge)ptr[i.from]++,ptr[i.to]++,seen[e.to]=true; for(int i=1;i<=n;i++)ptr[i]+=ptr[i-1]; r=std::find(seen.begin(),seen.end(),false)-seen.begin(); assert(ptr[n]==n*2-2); g.resize(ptr[n]); for(const Edge&i:edge)g[--ptr[i.to]]=Edge(i.to,i.from,i.weight,i.index); for(const Edge&i:edge)g[--ptr[i.from]]=i; } } template void read(){ for(int i=0;i>u>>v; if constexpr(index)u--,v--; if constexpr(weighted)std::cin>>w; else w=1; edge.emplace_back(u,v,w,i); } build(); } template void readp(){ ptr.resize(n+1); for(int i=1;i>p; if constexpr(index)p--; edge.emplace_back(p,i,1,i-1); ptr[p]++; ptr[i]++; } for(int i=1;i<=n;i++)ptr[i]+=ptr[i-1]; g.resize(n*2-2); for(auto&&[u,v,w,i]:edge)g[--ptr[v]]=Edge(v,u,w,i); for(int i=0;ipar(n,-1); par[root]=-1; std::queueque; que.push(root); while(!que.empty()){ int x=que.front(); que.pop(); for(int i=ptr[x];i&e=g[i]; if(e.to!=par[x]){ par[e.to]=x; assert(e.indexbfs_order()const{ assert(is_directed()); std::vectorbfs(n); int p=0,q=0; bfs[q++]=root(); while(p&e:(*this)[x])bfs[q++]=e.to; } return bfs; } std::vectordfs_order()const{ assert(is_directed()); std::vectorres; res.reserve(n); std::vectorst(n); int p=0; st[p++]=root(); while(p){ int x=st[--p]; res.push_back(x); p+=(*this)[x].size(); for(const Edge&e:(*this)[x])st[--p]=e.to; p+=(*this)[x].size(); } return res; } std::vectorrbfs_order()const{ std::vectorbfs=bfs_order(); std::reverse(bfs.begin(),bfs.end()); return bfs; } void hld(){ assert(is_directed()); std::vectorsub(n); for(int x:rbfs_order()){ sub[x]=1; int mx=-1; for(Edge&e:(*this)[x]){ sub[x]+=sub[e.to]; if(mx,std::vector>in_out_order(){ assert(is_directed()); std::vectorin(n),out(n); int p=0; auto dfs=[&](auto self,int x)->void { in[x]=p++; for(const Edge&e:(*this)[x]){ self(self,e.to); } out[x]=p; }; dfs(dfs,root()); return std::make_pair(in,out); } std::pair>diameter()const{ assert(!is_directed()); static constexpr T inf=std::numeric_limits::max(); std::vectordst(n,inf); dst[0]=0; std::vectorque(n); int p=0,q=1; que[0]=0; while(p&e:(*this)[x])if(dst[e.to]==inf){ dst[e.to]=dst[x]+e.weight; que[q++]=e.to; } } int u=std::max_element(dst.begin(),dst.end())-dst.begin(); std::fill(dst.begin(),dst.end(),inf); dst[u]=0; p=0,q=1; que[0]=u; while(p&e:(*this)[x])if(dst[e.to]==inf){ dst[e.to]=dst[x]+e.weight; que[q++]=e.to; } } int v=std::max_element(dst.begin(),dst.end())-dst.begin(); T weight=dst[v]; std::vectorres; while(u!=v){ res.push_back(v); for(const Edge&e:(*this)[v])if(dst[e.to]& get_edge(int i)const{return edge[i];} inline int parent(int i)const{return i==r?-1:g[ptr[i+1]-1].to;} inline int root()const{return r;} typename std::vector>::iterator begin(){return edge.begin();} typename std::vector>::iterator end(){return edge.end();} typename std::vector>::const_iterator begin()const{return edge.begin();} typename std::vector>::const_iterator end()const{return edge.end();} }; struct StaticTopTree{ private: template void build(Treet){ int n=t.size(); left.reserve(n*2-1),right.reserve(n*2-1),par.reserve(n*2-1),A.reserve(n*2-1),B.reserve(n*2-1); left.resize(n,-1),right.resize(n,-1),par.resize(n,-1),A.resize(n),B.resize(n); for(int i=0;istd::pair { std::vector>vs{{0,x}}; while(t[x].size()>=1){ std::priority_queue,std::vector>,std::greater>>que; int heavy=t[x][0].to; que.emplace(0,heavy); for(int i=1;i=2){ auto [d1,v1]=que.top();que.pop(); auto [d2,v2]=que.top();que.pop(); if(B[v2]==heavy)std::swap(d1,d2),std::swap(v1,v2); int nv=left.size(); left.push_back(v1),right.push_back(v2),par.push_back(-1),A.push_back(x),B.push_back(B[v1]); par[v1]=par[v2]=nv; que.emplace(std::max(d1,d2)+1,nv); } vs.push_back(que.top()); while(true){ int sz=vs.size(); if(sz>=3&&(vs[sz-3].first==vs[sz-2].first||vs[sz-3].first<=vs[sz-1].first)){ int nv=left.size(); left.push_back(vs[sz-3].second),right.push_back(vs[sz-2].second),par.push_back(-1),A.push_back(A[vs[sz-3].second]),B.push_back(B[vs[sz-2].second]); par[vs[sz-3].second]=par[vs[sz-2].second]=nv; vs[sz-3].first=std::max(vs[sz-3].first,vs[sz-2].first)+1; vs[sz-3].second=nv; vs[sz-2]=vs[sz-1]; vs.pop_back(); } else if(sz>=2&&vs[sz-2].first<=vs[sz-1].first){ int nv=left.size(); left.push_back(vs[sz-2].second),right.push_back(vs[sz-1].second),par.push_back(-1),A.push_back(A[vs[sz-2].second]),B.push_back(B[vs[sz-1].second]); par[vs[sz-2].second]=par[vs[sz-1].second]=nv; vs[sz-2].first=std::max(vs[sz-2].first,vs[sz-1].first)+1; vs[sz-2].second=nv; vs.pop_back(); } else break; } x=heavy; } while((int)vs.size()>=2){ int sz=vs.size(); int nv=left.size(); left.push_back(vs[sz-2].second),right.push_back(vs[sz-1].second),par.push_back(-1),A.push_back(A[vs[sz-2].second]),B.push_back(B[vs[sz-1].second]); par[vs[sz-2].second]=par[vs[sz-1].second]=nv; vs[sz-2].first=std::max(vs[sz-2].first,vs[sz-1].first)+1; vs[sz-2].second=nv; vs.pop_back(); } return vs[0]; }; dfs(dfs,t.root()); } public: std::vectorleft,right,par,A,B; StaticTopTree(){} template explicit StaticTopTree(Treet,int){ build(std::move(t)); } template explicit StaticTopTree(Treet){ assert(t.is_directed()); t.hld(); build(std::move(t)); } }; template struct CentroidDecomposition:public Tree{ private: using Tree::Tree; using Tree::g; using Tree::ptr; using Tree::remove_parent; using Tree::hld; int boundaryA1,boundaryB1,boundaryA2,boundaryB2; std::vector>adj1,adj2; bool prepared=false; StaticTopTree stt; void prepare(){ if(prepared)return; remove_parent(); hld(); stt=StaticTopTree(*this,0); prepared=true; } public: template void run(const Func&f){ prepare(); int n=this->size(); auto dfs=[&](auto self,int nd)->std::vector> { if(nd>res(1); if(nd==0)res[0]=Edge(-1,0); else{ res[0]=g[ptr[nd+1]-1]; std::swap(res[0].from,res[0].to); } return res; } int lv=stt.left[nd],rv=stt.right[nd]; std::vector>lch=self(self,lv); std::vector>rch=self(self,rv); boundaryA1=stt.A[lv]; boundaryB1=stt.B[lv]; boundaryA2=stt.A[rv]; boundaryB2=stt.B[rv]; std::swap(adj1,lch); std::swap(adj2,rch); f(boundaryA1,boundaryA2); std::swap(adj1,lch); std::swap(adj2,rch); if(boundaryA1==boundaryA2){ if(std::ssize(lch)::tree_range get(int c,int x){ if(c==0){ if(x==boundaryA1)return typename Tree::tree_range{adj1.begin(),adj1.end()}; if(x==boundaryB1)return typename Tree::tree_range{g.begin()+ptr[x+1]-(!!x),g.begin()+ptr[x+1]}; return typename Tree::tree_range{g.begin()+ptr[x],g.begin()+ptr[x+1]}; } else if(c==1){ if(x==boundaryA2)return typename Tree::tree_range{adj2.begin(),adj2.end()}; if(x==boundaryB2)return typename Tree::tree_range{g.begin()+ptr[x+1],g.begin()+ptr[x+1]}; return typename Tree::tree_range{g.begin()+ptr[x],g.begin()+ptr[x+1]}; } else std::abort(); } typename Tree::const_tree_range get(int c,int x)const{ if(c==0){ if(x==boundaryA1)return typename Tree::const_tree_range{adj1.begin(),adj1.end()}; if(x==boundaryB1)return typename Tree::const_tree_range{g.begin()+ptr[x+1]-(!!x),g.begin()+ptr[x+1]}; return typename Tree::const_tree_range{g.begin()+ptr[x],g.begin()+ptr[x+1]}; } else if(c==1){ if(x==boundaryA2)return typename Tree::const_tree_range{adj2.begin(),adj2.end()}; if(x==boundaryB2)return typename Tree::const_tree_range{g.begin()+ptr[x+1],g.begin()+ptr[x+1]}; return typename Tree::const_tree_range{g.begin()+ptr[x],g.begin()+ptr[x+1]}; } else std::abort(); } CentroidDecomposition(const Tree&t){Tree::operator=(t);} }; #include #include template constexpr std::enable_if_t::digits<=32,int>msb(T n){return n==0?-1:31-__builtin_clz(n);} template constexpr std::enable_if_t<(std::numeric_limits::digits>32),int>msb(T n){return n==0?-1:63-__builtin_clzll(n);} template constexpr std::enable_if_t::digits<=32,int>lsb(T n){return n==0?-1:__builtin_ctz(n);} template constexpr std::enable_if_t<(std::numeric_limits::digits>32),int>lsb(T n){return n==0?-1:__builtin_ctzll(n);} template constexpr std::enable_if_t,T>floor_pow2(T n){return n==0?0:T(1)< constexpr std::enable_if_t,T>ceil_pow2(T n){return n<=1?1:T(1)<<(msb(n-1)+1);} template constexpr T safe_div(T a,T b){return a/b-(a%b&&(a^b)<0);} template constexpr T safe_ceil(T a,T b){return a/b+(a%b&&(a^b)>0);} template struct SparseTable{ using S=typename M::S; private: std::vectordat,prefix,suffix; std::vector>sp; public: SparseTable(){} SparseTable(std::vectora):dat(a){ int n=a.size(); n=(n+(1<d2(n>>L,M::e()); for(int i=0;i<(int)d2.size();i++){ for(int j=0;j<(1<>L);i++){ for(int j=1;j<(1<>L)-1;i>=0;i--){ for(int j=(1<=1;j--)suffix[(i<=j-w;k--)sp[i][k]=M::op(d2[k],sp[i][k+1]); int r=std::min(d2.size(),j+w); for(int k=j+1;k>L,rid=r>>L; if(lid==rid){ S ret=M::e(); for(int i=l;i<=r;i++)ret=M::op(ret,dat[i]); return ret; } else{ lid++; rid--; S mid=M::e(); if(lid==rid)mid=sp[0][lid]; else if(lid; static S op(const S&x,const S&y){return x.first::max(),-1);} }; SparseTablesp; std::vectoridx; public: template LowestCommonAncestor(const Tree&t):idx(t.size()){ assert(t.is_directed()); int r=t.root(); int ord=0; std::vectordep(t.size()); dep[r]=0; std::vector>init(t.size()*2-1); auto dfs=[&](auto&&self,int x)->void { idx[x]=ord; init[ord++]=std::make_pair(dep[x],x); for(const auto&e:t[x]){ dep[e.to]=dep[e.from]+1; self(self,e.to); init[ord++]=std::make_pair(dep[x],x); } }; dfs(dfs,r); sp=SparseTable(init); } LowestCommonAncestor(){} int query(int u,int v)const{ if(u==v)return u; if(idx[u]>idx[v])std::swap(u,v); return sp.prod(idx[u],idx[v]+1).second; } }; using namespace std; template struct AuxiliaryTree{ private: vector>>g; LowestCommonAncestor lca; vectorin,out; vectordep; public: AuxiliaryTree(const Tree&t):g(t.size()),in(t.size()),out(t.size()){ assert(t.is_directed()); lca=LowestCommonAncestor(t); int root=t.root(); int i=0; dep.resize(t.size()); auto dfs=[&](auto&&self,int x,int p)->void { in[x]=i++; for(const auto&e:t[x])if(e.to!=p){ dep[e.to]=dep[e.from]+e.weight; self(self,e.to,e.from); } out[x]=i; }; dep[root]=0; dfs(dfs,root,-1); } AuxiliaryTree(){} int build(vectorv){ assert(!v.empty()); auto comp=[&](int x,int y)->bool {return in[x]st; for(int i=0;i<(int)v.size();i++){ while(!st.empty()&&out[st.top()]<=in[v[i]])st.pop(); if(!st.empty()){ T w=dep[v[i]]-dep[st.top()]; g[st.top()].push_back(Edge(st.top(),v[i],w)); g[v[i]].push_back(Edge(v[i],st.top(),w)); } st.push(v[i]); } while(st.size()>1)st.pop(); return st.top(); } vector> &operator[](int i){return g[i];} const vector> &operator[](int i)const{return g[i];} }; void SOLVE(){ int n; cin>>n; Tree t1(n),t2(n); t1.read(),t2.read(); ull ans=0; CentroidDecomposition cd(t1); t2.remove_parent(); AuxiliaryTree aux(t2); LowestCommonAncestor lca(t2); vectordep(n); for(int x:t2.bfs_order()){ for(auto e:t2[x])dep[e.to]=dep[e.from]+1; } vectorvs; vectortype(n,-1); vectordst(n); auto dfs=[&](auto self,int x,int p,int ban,int id)->void { if(x!=ban){ type[x]=id; vs.push_back(x); } for(auto e:cd.get(id,x))if(e.to!=p){ dst[e.to]=dst[x]+1; self(self,e.to,x,ban,id); } }; cd.run([&](int a1,int a2){ vs.clear(); dst[a2]=0; dfs(dfs,a2,-1,a1,0); int p=vs.size(); dfs(dfs,a2,-1,a2,1); ull dstsum1=0,depsum1=0; ull dstsum2=0,depsum2=0; rep(i,p){ dstsum1+=dst[vs[i]]; depsum1+=dep[vs[i]]; ans+=ull(dst[vs[i]])*dep[vs[i]]*(vs.size()-p); } rep(i,p,vs.size()){ dstsum2+=dst[vs[i]]; depsum2+=dep[vs[i]]; ans+=ull(dst[vs[i]])*dep[vs[i]]*p; } ans+=dstsum1*depsum2; ans+=dstsum2*depsum1; int root=aux.build(vs); auto dfs2=[&](auto self2,int x,int p)->tuple { ull sum1=0,cnt1=0; ull sum2=0,cnt2=0; for(auto e:aux[x])if(e.to!=p){ auto [sum11,cnt11,sum22,cnt22]=self2(self2,e.to,x); ans-=(sum1*cnt22+sum2*cnt11+sum11*cnt2+sum22*cnt1)*dep[x]*2; sum1+=sum11; cnt1+=cnt11; sum2+=sum22; cnt2+=cnt22; } if(type[x]!=-1){ if(type[x]==0){ ans-=(sum2+dst[x]*cnt2)*dep[x]*2; sum1+=dst[x]; cnt1++; } else{ ans-=(sum1+dst[x]*cnt1)*dep[x]*2; sum2+=dst[x]; cnt2++; } } return {sum1,cnt1,sum2,cnt2}; }; dfs2(dfs2,root,-1); for(int v:vs)type[v]=-1; }); ans*=2; cout<