#include using namespace std; class CD{ //Centroid-Decomposition public: int n = 0; long long suma = 0; vector A,par,cent; vector siz; vector already; vector> Graph; void make(vector> &G,vector B = {}){ //Bは頂点重み. n = G.size(); Graph = G; if(B.size()){A = B; for(auto &b : B) suma += b;} else A.resize(n,1),suma = n; siz.resize(n); par.resize(n); already.resize(n); } void findcentroid(int pos,int back,long long all){ //重心重み考慮. par.at(pos) = back; siz.at(pos) = A.at(pos); bool centroid = true; for(auto to : Graph.at(pos)){ if(to == back || already.at(to)) continue; findcentroid(to,pos,all); if(siz.at(to) > all/2) centroid = false; siz.at(pos) += siz.at(to); } if(all-siz.at(pos) > all/2) centroid = false; if(centroid) cent.push_back(pos); } void findcentroid2(int pos,int back,long long all){ //重心重み1. par.at(pos) = back; siz.at(pos) = 1; bool centroid = true; for(auto to : Graph.at(pos)){ if(to == back || already.at(to)) continue; findcentroid2(to,pos,all); if(siz.at(to) > all/2) centroid = false; siz.at(pos) += siz.at(to); } if(all-siz.at(pos) > all/2) centroid = false; if(centroid) cent.push_back(pos); } pair>> arrange(){ //メイン. int retroot = -1; vector> ret(n); queue> Q; Q.push({0,n,-1}); while(Q.size()){ auto[root,all,p] = Q.front(); Q.pop(); cent.clear(); findcentroid2(root,-1,all); int c = cent.at(0); already.at(c) = true; if(retroot == -1) retroot = c; if(p != -1) ret.at(p).push_back(c); for(auto to : Graph.at(c)){ if(already.at(to)) continue; if(to == par.at(c)) Q.push({to,all-siz.at(c),c}); else Q.push({to,siz.at(to),c}); } } return {retroot,ret}; } vector FindCentall(){ //1回重心求めるだけ cent.clear(); findcentroid(0,-1,suma); return cent; } int FindCentone(){vector R = FindCentall(); return R.at(0);} }; class SpecialSparseTable{ //LCA専用. private: int log = 0; pair op(pair &a,pair &b){return min(a,b);} pair add(pair &a,pair &b){return {a.first+b.first,a.second+b.second};} vector check,belong,Second; vector> Add; vector>>> Group; vector>> table; void maketable(vector> &A){ int n = A.size(); table.resize(n+1); check.resize(n+1); int p2 = 1; for(int i=1; i<=n; i++){ if(i == p2) check.at(i) = i,p2 *= 2; else check.at(i) = check.at(i-1); } table.at(1) = A; for(int i=2; i<=n; i*=2){ table.at(i).resize(n); for(int k=0; k<=n-i; k++) table[i][k] = op(table[i>>1][k],table[i>>1][k+(i>>1)]); } } void makeGroup(vector> &A){ int loop = 1<<(log-1); Group.resize(loop,vector>>(log,vector>(log))); for(int i=0; i now(1); for(int k=0; k now.at(r)) mina = now.at(r),pos = r; Group.at(i).at(l).at(r) = {mina,pos}; } } } } pair tablerange(int l,int r){//[L,R)だよ. int len = r-l,pos = check.at(len); return op(table.at(pos).at(l),table.at(pos).at(r-pos)); } public: void make(vector> &A){ int p2 = 1,n = A.size(); while(p2 < n) p2 *= 2,log++; log = max(1,(log+1)/2); vector> sepa; for(int i=0; i now = {1001001001,-1}; for(int k=i; k A.at(k)) now = {A.at(k).first,k}; } Add.push_back({A.at(i).first,i}); sepa.push_back(now); belong.push_back(g); } maketable(sepa); makeGroup(A); } int rangeans(int l,int r){ //[l,r)! int l2 = (l+log-1)/log,r2 = r/log; pair mind = {1001001001,-1}; if(l2 > r2) mind = add(Group[belong[r2]][l%log][(r-1)%log],Add[r2]); else{ if(l2 < r2) mind = tablerange(l2,r2); if(l%log) mind = min(mind,add(Group[belong[l2-1]][l%log][log-1],Add[l2-1])); if(r%log) mind = min(mind,add(Group[belong[r2]][0][(r-1)%log],Add[r2])); } return Second.at(mind.second); } }; class LCA{ private: vector dist,in,out; SpecialSparseTable ST; public: void make1(vector &P){// p0=-1でp1以降だけ int r = 0; vector> G(P.size()+1); for(int i=0; i &P){//pi=-1 iは固定されていない. int r = -1; vector> G(P.size()); for(int i=0; i> &Graph,int root){ //直接グラフを渡す. int t = 0,dep = 0,n = Graph.size(),pos = root; dist.resize(n),in.resize(n),out.resize(n); vector> depth; vector Itr(n,-1),P(n,-1); while(pos != -1){ depth.push_back({dep,pos}); if(++Itr.at(pos) == 0) in.at(pos) = t; int to = P.at(pos); if(Itr.at(pos) == Graph.at(pos).size()) out.at(pos) = ++t; else{ to = Graph.at(pos).at(Itr.at(pos)); if(to == P.at(pos)){ Itr.at(pos)++; if(Itr.at(pos) == Graph.at(pos).size()) out.at(pos) = ++t; else to = Graph.at(pos).at(Itr.at(pos)); } } if(to != P.at(pos)) dist.at(to) = dist.at(pos)+1,P.at(to) = pos,t++,dep++; else dep--; pos = to; } ST.make(depth); } int lca(int u,int v){ int tu = in.at(u),tv = in.at(v); if(tu > tv) swap(tu,tv); return ST.rangeans(tu,tv+1); } int twodist(int u,int v){return dist.at(u)+dist.at(v)-2*dist.at(lca(u,v));} int onedist(int u){return dist.at(u);} }; int main(){ ios_base::sync_with_stdio(false); cin.tie(nullptr); int N; cin >> N; vector> Graph(N); for(int i=0; i> u >> v; u--; v--; Graph.at(u).push_back(v); Graph.at(v).push_back(u); } LCA L; L.make3(Graph,0); CD Z; Z.make(Graph); auto [root,Graph2] = Z.arrange(); vector par(N); auto dfs = [&](auto dfs,int pos,int back) -> void { par.at(pos) = back; for(auto to : Graph2.at(pos)) dfs(dfs,to,pos); }; dfs(dfs,root,-1); int Q; cin >> Q; vector Black(N); vector,vector>,greater<>>> Qs(N); while(Q--){ int t,v; cin >> t >> v; v--; if(t == 1){ if(Black.at(v)) Black.at(v) = false; else{ Black.at(v) = true; int pos = v; while(pos != -1) Qs.at(pos).push({L.twodist(v,pos),v}),pos = par.at(pos); } } else{ int pos = v,answer = 1001001001; while(pos != -1){ while(Qs.at(pos).size()){ auto [d,p] = Qs.at(pos).top(); if(Black.at(p) == false) Qs.at(pos).pop(); else{answer = min(answer,L.twodist(v,p)); break;} } pos = par.at(pos); } cout << answer << "\n"; } } }