結果
| 問題 | No.2337 Equidistant |
| ユーザー |
 noya2
|
| 提出日時 | 2023-06-02 22:36:21 |
| 言語 | C++17 (gcc 12.3.0 + boost 1.83.0) |
| 結果 |
AC
|
| 実行時間 | 1,181 ms / 4,000 ms |
| コード長 | 17,572 bytes |
| コンパイル時間 | 5,921 ms |
| コンパイル使用メモリ | 289,440 KB |
| 実行使用メモリ | 101,828 KB |
| 最終ジャッジ日時 | 2023-08-28 04:44:49 |
| 合計ジャッジ時間 | 20,391 ms |
|
ジャッジサーバーID （参考情報） |
judge12 / judge11 |
（要ログイン）
テストケース
テストケース表示| 入力 | 結果 | 実行時間 実行使用メモリ |
|---|---|---|
| testcase_00 | AC | 1 ms
4,376 KB |
| testcase_01 | AC | 2 ms
4,376 KB |
| testcase_02 | AC | 1 ms
4,380 KB |
| testcase_03 | AC | 2 ms
4,376 KB |
| testcase_04 | AC | 2 ms
4,376 KB |
| testcase_05 | AC | 2 ms
4,380 KB |
| testcase_06 | AC | 4 ms
4,376 KB |
| testcase_07 | AC | 4 ms
4,376 KB |
| testcase_08 | AC | 4 ms
4,376 KB |
| testcase_09 | AC | 4 ms
4,380 KB |
| testcase_10 | AC | 4 ms
4,376 KB |
| testcase_11 | AC | 640 ms
58,248 KB |
| testcase_12 | AC | 633 ms
58,088 KB |
| testcase_13 | AC | 651 ms
57,960 KB |
| testcase_14 | AC | 652 ms
57,964 KB |
| testcase_15 | AC | 640 ms
57,972 KB |
| testcase_16 | AC | 657 ms
58,108 KB |
| testcase_17 | AC | 641 ms
57,912 KB |
| testcase_18 | AC | 633 ms
57,948 KB |
| testcase_19 | AC | 654 ms
58,152 KB |
| testcase_20 | AC | 656 ms
58,292 KB |
| testcase_21 | AC | 789 ms
101,828 KB |
| testcase_22 | AC | 730 ms
57,200 KB |
| testcase_23 | AC | 532 ms
58,008 KB |
| testcase_24 | AC | 1,063 ms
87,436 KB |
| testcase_25 | AC | 571 ms
57,796 KB |
| testcase_26 | AC | 1,181 ms
86,824 KB |
| testcase_27 | AC | 595 ms
57,876 KB |
| testcase_28 | AC | 586 ms
57,844 KB |
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 noya2
using 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 tree
naiveTree (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 tree
usefulTree (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 holded
while (_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 id
seg.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 < n
es[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 point
for (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 point
for (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 i
vector<int> order, edges, whose; // order[i] is ith vertex visited on Euler tour, vertex v has edges[v] (root has no edge), edges^-1 = whose
void 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-1
order[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();
}