結果
問題 | No.2337 Equidistant |
ユーザー |
![]() |
提出日時 | 2023-06-02 22:36:21 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 1,193 ms / 4,000 ms |
コード長 | 17,572 bytes |
コンパイル時間 | 5,154 ms |
コンパイル使用メモリ | 279,680 KB |
最終ジャッジ日時 | 2025-02-13 19:31:50 |
ジャッジサーバーID (参考情報) |
judge5 / judge2 |
(要ログイン)
ファイルパターン | 結果 |
---|---|
sample | AC * 1 |
other | AC * 28 |
ソースコード
#line 1 "c.cpp"#include<bits/stdc++.h>#include<atcoder/all>#define rep(i,n) for (int i = 0; i < int(n); ++i)#define repp(i,m,n) for (int i = m; i < int(n); ++i)#define reb(i,n) for (int i = int(n)-1; i >= 0; --i)#define all(v) v.begin(),v.end()using namespace std;using namespace atcoder;using ll = long long;using ull = unsigned long long;using ld = long double;using P = pair<int, int>;using PL = pair<long long, long long>;using pdd = pair<long double, long double>;using pil = pair<int,ll>;using pli = pair<ll,int>;template<class T>istream &operator>>(istream &is,vector<T> &v){for(auto &e:v)is>>e;return is;}template<typename T>bool range(T a,T b,T x){return (a<=x&&x<b);}template<typename T>bool rrange(T a,T b,T c,T d,T x,T y){return (range(a,c,x)&&range(b,d,y));}template<typename T> T rev(const T& str_or_vec){T res = str_or_vec; reverse(res.begin(),res.end()); return res; }template<typename T>bool chmin(T &a,const T &b){if(a>b){a=b;return true;}return false;}template<typename T>bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}template<typename T>void uniq(vector<T> &v){sort(v.begin(),v.end());v.erase(unique(v.begin(),v.end()),v.end());}template<typename T1, typename T2>void print(pair<T1,T2> a);template<typename T>void print(vector<T> v);template<typename T>void print(vector<vector<T>> v);void print(){ putchar(' '); }void print(bool a){ printf("%d", a); }void print(int a){ printf("%d", a); }void print(long a){ printf("%ld", a); }void print(long long a){ printf("%lld", a); }void print(char a){ printf("%c", a); }void print(char a[]){ printf("%s", a); }void print(const char a[]){ printf("%s", a); }void print(long double a){ printf("%.15Lf", a); }void print(const string& a){ for(auto&& i : a) print(i); }void print(unsigned int a){ printf("%u", a); }void print(unsigned long long a) { printf("%llu", a); }template<class T> void print(const T& a){ cout << a; }int out(){ putchar('\n'); return 0; }template<class T> int out(const T& t){ print(t); putchar('\n'); return 0; }template<class Head, class... Tail> int out(const Head& head, const Tail&... tail){ print(head); putchar(' '); out(tail...); return 0; }template<typename T1,typename T2>void print(pair<T1,T2> a){print(a.first);print(),print(a.second);}template<typename T>void print(vector<T> v){for(auto ite=v.begin();ite!=v.end();){print(*ite);if(++ite!=v.end())print();}}template<typename T>void print(vector<vector<T>> v){for(auto ite=v.begin();ite!=v.end();){print(*ite);if(++ite!=v.end())out();}}void yes(){out("Yes");}void no (){out("No");}void yn (bool t){if(t)yes();else no();}void fast_io(){cin.tie(0); ios::sync_with_stdio(0); cout<<fixed<<setprecision(20);}void o(){out("!?");}namespace noya2{const int INF = 1001001007;const long long mod1 = 998244353;const long long mod2 = 1000000007;const long long inf = 2e18;const long double pi = 3.14159265358979323;const long double eps = 1e-7;const vector<int> dx = {0,1,0,-1,1,1,-1,-1};const vector<int> dy = {1,0,-1,0,1,-1,-1,1};const string ALP = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";const string alp = "abcdefghijklmnopqrstuvwxyz";const string NUM = "0123456789";} // namespace noya2using namespace noya2;using mint = modint998244353;//using mint = modint1000000007;//using mint = modint;void out(mint a){out(a.val());}void out(vector<mint> a){vector<ll> b(a.size()); rep(i,a.size()) b[i] = a[i].val(); out(b);}void out(vector<vector<mint>> a){for (auto v : a) out(v);}#line 2 "rerooting_new.hpp"#line 4 "rerooting_new.hpp"namespace noya2 {using namespace std;template<class E, class V, E (*merge)(E, E), E (*e)(), E (*put_edge)(V, int), V (*put_vertex)(E, int)>struct Rerooting {struct edge{int to, idx, xdi;};Rerooting (int _n = 0) : n(_n) { es.resize(n);}void add_edge(int u, int v, int idx1, int idx2){es[u].push_back({v,idx1,idx2});es[v].push_back({u,idx2,idx1});}vector<V> build(int v = 0){root = v;outs.resize(n);subdp.resize(n);in.resize(n), up.resize(n);int tnow = 0;dfs(root,-1,tnow);return subdp;}vector<V> reroot(){reverse_edge.resize(n);reverse_edge[root] = e();reverse_dp.resize(n);answers.resize(n);bfs(root);return answers;}V get(int r, int v){if (r == v) return answers[r];if (!(in[v] < in[r] && up[r] <= up[v])) return subdp[v];int le = 0, ri = outs[v].size();while (ri - le > 1){int md = (le + ri) / 2;if (in[es[v][md].to] <= in[r]) le = md;else ri = md;}return reverse_dp[es[v][le].to];}const vector<edge>& operator[](int idx) const { return es[idx]; }private:int n, root;vector<vector<edge>> es;vector<vector<E>> outs;vector<E> reverse_edge;vector<V> subdp, reverse_dp, answers;vector<int> in, up;void dfs(int v, int p, int &t){E val = e();in[v] = t++;for (auto &u : es[v]){if (u.to == p && u.to != es[v].back().to) swap(u,es[v].back());if (u.to == p) continue;dfs(u.to,v,t);E nval = put_edge(subdp[u.to],u.idx);outs[v].emplace_back(nval);val = merge(val,nval);}subdp[v] = put_vertex(val,v);up[v] = t;}void bfs(int v){int siz = outs[v].size();vector<E> lui(siz+1), rui(siz+1);lui[0] = e(), rui[siz] = e();for (int i = 0; i < siz; i++) lui[i+1] = merge(lui[i],outs[v][i]);for (int i = siz-1; i >= 0; i--) rui[i] = merge(outs[v][i],rui[i+1]);for (int i = 0; i < siz; i++){reverse_dp[es[v][i].to] = put_vertex(merge(merge(lui[i],rui[i+1]),reverse_edge[v]),v);reverse_edge[es[v][i].to] = put_edge(reverse_dp[es[v][i].to],es[v][i].xdi);bfs(es[v][i].to);}answers[v] = put_vertex(merge(lui[siz],reverse_edge[v]), v);}};} // namespace noya2#line 2 "Tree-core.hpp"#line 5 "Tree-core.hpp"namespace noya2 {using namespace std;struct naiveTree { // undirected unweighted treenaiveTree (int _n = 0) : n(_n){ init();}void add_edge(int u, int v, int id = -1){es0[u].emplace_back(v);es0[v].emplace_back(u);es1[u].emplace_back(v,id);es1[v].emplace_back(u,id);}void remake(int new_n){es0.clear(); es1.clear(); vis.clear();n = new_n;init();}bool yet(int v){ return vis[v] == 0;}void visit(int v) { vis[v]++;}void reset(int v = -1){if (v == -1) fill(vis.begin(),vis.end(),0);else vis[v] = 0;}const vector<int>& operator[](int idx) const { return es0[idx];}const vector<pair<int,int>>& operator()(int idx) const {return es1[idx];}private:int n;vector<vector<int>> es0;vector<vector<pair<int,int>>> es1;vector<int> vis;void init(){es0.resize(n);es1.resize(n);vis.resize(n,0);}};struct usefulTree { // rooted treeusefulTree (int _n = 0, int _root = 0) : n(_n), root(_root) { init();}void add_edge(int u, int v){es[u].emplace_back(v);es[v].emplace_back(u);}void remake(int new_n, int new_root = 0){es.clear(); vis.clear();n = new_n, root = new_root;init();}bool yet(int v){ return vis[v] == 0;}void visit(int v) { vis[v]++;}void reset(int v = -1){if (v == -1) fill(vis.begin(),vis.end(),0);else vis[v] = 0;}const vector<int>& operator[](int idx) const { return es[idx];}int parent(int v){ return par[0][v];}int subtree_size(int v){if (sub[v] != -1) return sub[v];sub[v] = 1;for (int child : es[v]){if (child != par[0][v]) sub[v] += subtree_size(child);}return sub[v];}int depth(int v){ return dep[v];}int lca(int u, int v){if (dep[u] > dep[v]) swap(u,v);for (int i = 0; i < p2size; i++) if ((dep[v] - dep[u]) >> i & 1) v = par[i][v];if (u == v) return u;for (int i = p2size-1; i >= 0; i--){if (par[i][u] != par[i][v]){u = par[i][u];v = par[i][v];}}return par[0][u];}int jump_to_root(int from, int d){for (int i = 0; i < p2size; i++){if ((d >> i & 1) == 1 && from != -1) from = par[i][from];}return from;}int jump(int from, int to, int d){int l = lca(from,to);if (d <= dep[from] - dep[l]){return jump_to_root(from,d);}d -= dep[from] - dep[l];if (d <= dep[to] - dep[l]){return jump_to_root(to,dep[to]-dep[l]-d);}return -1;}vector<int> path(int from, int to){int l = lca(from,to);int nf = from, nt = to;vector<int> pf = {from}, pt = {to};while (nf != l){nf = par[0][nf];pf.emplace_back(nf);}while (nt != l){nt = par[0][nt];pt.emplace_back(nt);}for (int i = pt.size()-2; i >= 0; i--) pf.emplace_back(pt[i]);return pf;}int dist(int u, int v){ return dep[u] + dep[v] - 2 * dep[lca(u,v)];}void build(){par.clear();dep.clear();sub.clear();p2size = 1;int _ni = 1; // _ni = 2^(p2size - 1), n-1 <= 2^(p2size - 1) must be holdedwhile (_ni < n-1) p2size++, _ni <<= 1;par.resize(p2size,vector<int>(n,-1));dep.resize(n,-1);sub.resize(n,-1);queue<int> que;que.push(root);dep[root] = 0;while (!que.empty()){int p = que.front(); que.pop();for (int to : es[p]){if (dep[to] == -1){par[0][to] = p;dep[to] = dep[p] + 1;que.push(to);}}}for (int i = 1; i < p2size; i++){for (int v = 0; v < n; v++){if (par[i-1][v] == -1) continue;par[i][v] = par[i-1][par[i-1][v]];}}}private:int n, root;vector<vector<int>> es;vector<int> vis;int p2size;vector<vector<int>> par;vector<int> dep, sub;void init(){es.resize(n);vis.resize(n,0);}};/* point hld (commutative)vector<S> a(n); // vertex v has a[v]hldTree g(n);segtree<S,op,e> seg(n);rep(i,n) seg.set(i,a[g.ord(i)]); // pre <-> ord (pre(v) = i, ord(i) = v)update query :int v; S x; cin >> v >> x;seg.set(g.pre(v),x);product query :S ans = e();auto f = [&](int l, int r){ans = op(ans,seg.prod(l,r));};int u, v; cin >> u >> v;ans = e();g.path_query(u, v, true, f);cout << ans << endl;*//* edge hld (commutative)vector<S> b(n-1); // edge i has b[i]vector<S> a(n); // vertex v has a[v]rep(v,n) a[v] = (v == root ? e() : b[g.edge(v)]);update query :int id; S x; cin >> id >> x; // edge idseg.set(g.pre(who(id)),x); // edge <-> who (edge(v) = i, who(i) = v)*/struct hldTree {hldTree (int _n = 0, int _root = 0) : n(_n), root(_root) { init();}void add_edge(int u, int v, int id){ // id must be 0 <= id < nes[u].emplace_back(v,id);es[v].emplace_back(u,id);}void remake(int new_n, int new_root = 0){es.clear(); size.clear(); par.clear(); dep.clear(); up.clear(); down.clear();nxt.clear(); order.clear(); edges.clear(); whose.clear();n = new_n, root = new_root;init();}void build(){dfs_init(root);int t = 0;dfs_hld(root,t);}int lca(int u, int v){while (nxt[u] != nxt[v]){if (down[u] < down[v]) swap(u,v);u = par[nxt[u]];}return dep[u] < dep[v] ? u : v;}int dist(int u, int v){return dep[u] + dep[v] - 2 * dep[lca(u,v)];}int parent(int v){ return par[v];}int depth(int v){ return dep[v];}int subtree_size(int v){ return size[v];}int pre(int v){ return down[v];}int post(int v){ return up[v];}int ord(int i){ return order[i];}int who(int i){ return whose[i];}int edge(int v){ return edges[v];}template<typename F>void path_query(int u, int v, bool vertex, const F &f){ // f is function takes (left, right) as argument, range = [left,right).int l = lca(u,v);for (auto &p : ascend(u,l)){int s = p.first + 1, t = p.second; // p.first + 1 : depth(p.first) > depth(p.second), so [p.second,p.first] = [p.second,p.first+1)s > t ? f(t,s) : f(s,t);}if (vertex) f(down[l],down[l]+1); // vertex is true : query is for pointfor (auto &p : descend(l,v)){int s = p.first, t = p.second + 1; // p.second +1 : depth(p.first) < depth(p.second), so [p.first,p.second] = [p.first,p.second+1)s > t ? f(t,s) : f(s,t);}}template<typename F>void path_noncommutative_query(int u, int v, bool vertex, const F &f){ // op(l,r) != op(r,l), so prod[u->...->v] != prod[v->...->u]int l = lca(u,v);for (auto &p : ascend(u,l)){int s = p.first + 1, t = p.second; // p.first + 1 : depth(p.first) > depth(p.second), so [p.second,p.first] = [p.second,p.first+1)f(s,t); // le > ri ok}if (vertex) f(down[l],down[l]+1); // vertex is true : query is for pointfor (auto &p : descend(l,v)){int s = p.first, t = p.second + 1; // p.second +1 : depth(p.first) < depth(p.second), so [p.first,p.second] = [p.first,p.second+1)f(s,t); // le > ri ok}}template<typename F>void subtree_query(int v, bool vertex, const F &f){f(down[v] + (vertex ? 0 : 1), up[v]);}const vector<pair<int,int>>& operator()(int idx) const { return es[idx];}private:int n, root;vector<vector<pair<int,int>>> es;vector<int> size, par, dep, up, down, nxt; // nxt[i] : most shallow vertex in connected component of vertex ivector<int> order, edges, whose; // order[i] is ith vertex visited on Euler tour, vertex v has edges[v] (root has no edge), edges^-1 = whosevoid init(){es.resize(n);size.resize(n,0);par.resize(n,root);dep.resize(n,0);up.resize(n,-1);down.resize(n,-1);nxt.resize(n,root);order.resize(n,-1);edges.resize(n,-1);whose.resize(n,-1);}void dfs_init(int cur){size[cur] = 1;for (auto &e : es[cur]){if (e.first == par[cur]){if (es[cur].size() >= 2 && e.first == es[cur][0].first){swap(es[cur][0],es[cur][1]); // if cur is not leaf, vs[cur][0] is not cur's parent}else continue;}par[e.first] = cur;edges[e.first] = e.second;whose[e.second] = e.first;dep[e.first] = dep[cur] + 1;dfs_init(e.first);size[cur] += size[e.first];if (size[e.first] > size[es[cur][0].first]){swap(e,es[cur][0]); // to maximize vs[cur][0]'s subtree_size}}}void dfs_hld(int cur, int &tnow){down[cur] = tnow++; // down[0,...,n-1] is permutation of 0,...,n-1order[down[cur]] = cur;for (auto e : es[cur]){if (e.first == par[cur]) continue;nxt[e.first] = (e.first == es[cur][0].first ? nxt[cur] : e.first);dfs_hld(e.first,tnow);}up[cur] = tnow; // up[0,...,n-1] is NOT permutation, up[*] <= n}vector<pair<int,int>> ascend(int u, int v) const { // [u,v), depth[u] > depth[v]vector<pair<int,int>> res;while (nxt[u] != nxt[v]){res.emplace_back(down[u],down[nxt[u]]); // [s1,t1], [s2,t2], ...u = par[nxt[u]];}if (u != v) res.emplace_back(down[u],down[v]+1); // [s,t). v is not in the range (down[] is ordered opposite direction of depth)return res;}vector<pair<int,int>> descend(int u, int v) const { // (u,v], depth[u] < depth[v]if (u == v) return {};if (nxt[u] == nxt[v]){return {pair<int,int>(down[u]+1,down[v])}; // (s,t]. u is not in the range}vector<pair<int,int>> res = descend(u,par[nxt[v]]);res.emplace_back(down[nxt[v]],down[v]); // [s1,t1], [s2,t2], ...return res;}};} // namespace noya2#line 78 "c.cpp"int op(int a, int b){return a + b;}int e(){return 0;}int pute(int e, int i){return e;}int putv(int v, int i){return v + 1;}void solve(){int n, q; cin >> n >> q;usefulTree g(n);Rerooting<int,int,op,e,pute,putv> rg(n);rep(i,n-1){int u, v; cin >> u >> v; u--, v--;g.add_edge(u,v);rg.add_edge(u,v,i,i);}g.build();rg.build();rg.reroot();while (q--){int u, v; cin >> u >> v; u--, v--;int d = g.dist(u,v);if (d % 2 == 1){out(0);continue;}int c = g.jump(u,v,d/2);out(rg.get(u,c) + rg.get(v,c) - n);}}int main(){fast_io();int t = 1; //cin >> t;while(t--) solve();}