結果
| 問題 | No.2337 Equidistant |
| ユーザー |
 Kyo_s_s
|
| 提出日時 | 2023-06-03 10:17:28 |
| 言語 | C++17 (gcc 12.3.0 + boost 1.83.0) |
| 結果 |
AC
|
| 実行時間 | 938 ms / 4,000 ms |
| コード長 | 9,902 bytes |
| コンパイル時間 | 2,973 ms |
| コンパイル使用メモリ | 226,864 KB |
| 実行使用メモリ | 51,104 KB |
| 最終ジャッジ日時 | 2024-06-09 03:22:00 |
| 合計ジャッジ時間 | 13,141 ms |
|
ジャッジサーバーID （参考情報） |
judge2 / judge3 |
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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 | 2 ms
6,812 KB |
| testcase_01 | AC | 2 ms
6,940 KB |
| testcase_02 | AC | 1 ms
6,944 KB |
| testcase_03 | AC | 2 ms
6,944 KB |
| testcase_04 | AC | 1 ms
6,944 KB |
| testcase_05 | AC | 1 ms
6,940 KB |
| testcase_06 | AC | 4 ms
6,944 KB |
| testcase_07 | AC | 3 ms
6,940 KB |
| testcase_08 | AC | 4 ms
6,944 KB |
| testcase_09 | AC | 4 ms
6,944 KB |
| testcase_10 | AC | 4 ms
6,940 KB |
| testcase_11 | AC | 379 ms
33,580 KB |
| testcase_12 | AC | 372 ms
33,580 KB |
| testcase_13 | AC | 386 ms
33,584 KB |
| testcase_14 | AC | 404 ms
33,580 KB |
| testcase_15 | AC | 372 ms
33,580 KB |
| testcase_16 | AC | 409 ms
33,576 KB |
| testcase_17 | AC | 399 ms
33,584 KB |
| testcase_18 | AC | 370 ms
33,580 KB |
| testcase_19 | AC | 372 ms
33,576 KB |
| testcase_20 | AC | 343 ms
33,576 KB |
| testcase_21 | AC | 501 ms
51,104 KB |
| testcase_22 | AC | 308 ms
34,512 KB |
| testcase_23 | AC | 323 ms
34,848 KB |
| testcase_24 | AC | 685 ms
44,856 KB |
| testcase_25 | AC | 374 ms
34,840 KB |
| testcase_26 | AC | 938 ms
44,760 KB |
| testcase_27 | AC | 409 ms
34,716 KB |
| testcase_28 | AC | 406 ms
34,732 KB |
ソースコード
#include <bits/stdc++.h>
using namespace std;
// #include <atcoder/all>
// using namespace atcoder;
/* alias */
using ull = unsigned long long;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vll = vector<long long>;
using vd = vector<double>;
using vs = vector<string>;
using vb = vector<bool>;
using vpii = vector<pair<int, int>>;
using vpll = vector<pair<ll, ll>>;
using vvi = vector<vector<int>>;
using vvll = vector<vector<long long>>;
using vvd = vector<vector<double>>;
using vvs = vector<vector<string>>;
using vvb = vector<vector<bool>>;
template<typename T> using min_priority_queue = priority_queue<T, vector<T>, greater<T>>;
/* define */
#define MOD 998244353
// #define MOD 1000000007
#define INF (1LL << 60)
#define elif else if
#define pb push_back
#define pf push_front
#define fi first
#define se second
#define all(obj) (obj).begin(), (obj).end()
#define YESNO(bool) cout << (bool ? "YES\n" : "NO\n")
#define YesNo(bool) cout << (bool ? "Yes\n" : "No\n")
#define yesno(bool) cout << (bool ? "yes\n" : "no\n")
template<class T> bool chmax(T &a, const T &b) {if(a<b){ a=b; return 1;} return 0;}
template<class T> bool chmin(T &a, const T &b) {if(b<a){ a=b; return 1;} return 0;}
#define debug(x) cerr << #x << ":" << x << "\n";
/* REP macro */
#define reps(i, a, n) for(ll i = (a); i < (n); i++)
#define rep(i, n) reps(i, 0, (n))
#define rrep(i, n) reps(i, 1, (n + 1))
#define repd(i, n) for(ll i = (n - 1); i >= 0; i--)
#define rrepd(i, n) for(ll i = (n); i >= 1; i--)
#define fore(i, a) for(auto &i: a)
/* vector */
template<class T> T vmax(vector<T> &array){ T ret = array[0]; for(T a: array) chmax(ret, a); return ret; }
template<class T> T vmin(vector<T> &array){ T ret = array[0]; for(T a: array) chmin(ret, a); return ret; }
template<class T> T sum(vector<T> &array){ T ret = 0; for(T a:array) ret += a; return ret; }
template<class T> void list_set(vector<T> &array){ sort(all(array)); array.erase(unique(all(array)),array.end()); }
template<class T> int bisect_left(vector<T> &array, T key){ return lower_bound(all(array),key) - array.begin(); }
template<class T> int bisect_right(vector<T> &array, T key){ return upper_bound(all(array),key) - array.begin(); }
/* string */
ll string_to_ll(string n){ ll ret = 0, k = 1; while(n.length() > 0){ ret += k * (n.back() - '0'); n.pop_back(); k *= 10; } return ret; }
string ll_to_string(ll n){ string ret = ""; while(n > 0){ ret.pb((n % 10) + '0'); n /= 10; } reverse(all(ret)); return ret; }
struct popopo{ popopo(){ cin.tie(0); ios::sync_with_stdio(0); cout << fixed << setprecision(15); }; } popopoppo;
// n = 1,...,N に対して、n % A < B を満たすものの数
ll Count_of_n_mod_A_less_than_B(ll N, ll A, ll B){ return N / A * min(A, B) + min(N % A, B - 1); }
bool include(ll l, ll r, ll x) { return l <= x && x < r; }
/* IN/OUT */
int scan() { return getchar(); }
void scan(int &a) { cin >> a; }
void scan(long long &a) { cin >> a; }
void scan(char &a) { cin >> a; }
void scan(double &a) { cin >> a; }
void scan(string &a) { cin >> a; }
template <class T, class S> void scan(pair<T, S> &p) { scan(p.first), scan(p.second); }
template <class T> void scan(vector<T> &);
template <class T> void scan(vector<T> &a) { for(auto &i : a) scan(i); }
void IN(){}
template<class Head, class... Tail> void IN(Head& head, Tail &...tail){ scan(head); IN(tail...); }
#define INT(...) int __VA_ARGS__; IN(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__; IN(__VA_ARGS__)
#define STR(...) string __VA_ARGS__; IN(__VA_ARGS__)
#define VEC(type, name, size) vector<type> name(size); IN(name)
#define VECS(type, name, size) vector<type> name(size + 1); for(int i = 1; i <= size; i++) scan(name[i])
void OUT(){ cout << "\n"; }
template<class T> void output(T a){ cout << a; }
template<class T> void output(vector<T> v){ for(int i = 0; i < v.size(); i++) cout << v[i] << (i == v.size() - 1 ? "" : " "); }
template<class Head, class... Tail> void OUT(const Head &head, const Tail &...tail) { output(head); if(sizeof...(tail)) cout << " "; OUT(tail...); }
void FLASH(){ cout << endl; }
template<class Head, class... Tail> void FLASH(const Head &head, const Tail &...tail) { output(head); if(sizeof...(tail)) cout << " "; FLASH(tail...); }
namespace kyo {
long long bisect(long long ok, long long ng, function<bool(long long)> is_ok) { while (abs(ok - ng) > 1) { long long mid = ok + (ng - ok) / 2; (is_ok(mid) ? ok : ng) = mid; } return ok; }
}
template<class T = int> struct Tree {
struct edge{ int to; T cost; };
vector<vector<edge>> G;
vector<vector<int>> parent;
vector<int> unweighted_dist;
vector<T> weighted_dist;
Tree(int n) : G(n) {}
void add_edge(int u, int v) { add_edge(u, v, T(1)); }
void add_edge(int u, int v, T w) {
G[u].push_back({v, w});
G[v].push_back({u, w});
}
vector<int> get_count(int root = 0) {
vector<int> count(G.size(), 0);
function<void(int, int)> dfs = [&](int v, int p) {
count[v] = 1;
for (auto e: G[v]) {
if (e.to == p) continue;
dfs(e.to, v);
count[v] += count[e.to];
}
};
dfs(root, -1);
return count;
}
vector<T> calc_dist(int root = 0) {
vector<T> dist(G.size(), -1); dist[root] = 0;
queue<int> que; que.push(root);
while (!que.empty()) {
int v = que.front(); que.pop();
for (auto e: G[v]) {
if (dist[e.to] != -1) continue;
dist[e.to] = dist[v] + e.cost;
que.push(e.to);
}
}
return dist;
}
tuple<T, int, int> diameter() {
vector<T> dist = calc_dist();
int v = max_element(dist.begin(), dist.end()) - dist.begin();
dist = calc_dist(v);
int u = max_element(dist.begin(), dist.end()) - dist.begin();
return { dist[u], u, v };
}
vector<int> path(int u, int v) {
vector<T> dist = calc_dist(u);
vector<int> path;
while (v != u) {
path.push_back(v);
for (auto e: G[v]) {
if (dist[e.to] == dist[v] - e.cost) {
v = e.to;
break;
}
}
}
path.push_back(u);
reverse(path.begin(), path.end());
return path;
}
void lca_build(int root = 0) {
int V = G.size();
int K = 1;
while ((1 << K) < V) K++;
parent.assign(K, vector<int>(V, -1));
unweighted_dist.assign(V, -1);
auto unweighted_dfs = [this](auto&& self, int v, int p, int d) -> void {
parent[0][v] = p;
unweighted_dist[v] = d;
for (auto e: G[v]) {
if (e.to == p) continue;
self(self, e.to, v, d + 1);
}
};
unweighted_dfs(unweighted_dfs, root, -1, 0);
for (int k = 0; k + 1 < K; k++) {
for (int v = 0; v < V; v++) {
if (parent[k][v] < 0) parent[k + 1][v] = -1;
else parent[k + 1][v] = parent[k][parent[k][v]];
}
}
weighted_dist.assign(V, -1); weighted_dist[root] = 0;
queue<int> que; que.push(root);
while (!que.empty()) {
int v = que.front(); que.pop();
for (auto e: G[v]) {
if (weighted_dist[e.to] == -1 || weighted_dist[e.to] > weighted_dist[v] + e.cost) {
weighted_dist[e.to] = weighted_dist[v] + e.cost;
que.push(e.to);
}
}
}
}
int lca(int u, int v) {
if (parent.size() == 0) lca_build();
if (unweighted_dist[u] < unweighted_dist[v]) swap(u, v);
int K = parent.size();
for (int k = 0; k < K; k++) {
if ((unweighted_dist[u] - unweighted_dist[v]) >> k & 1) {
u = parent[k][u];
}
}
if (u == v) return u;
for (int k = K - 1; k >= 0; k--) {
if (parent[k][u] != parent[k][v]) {
u = parent[k][u];
v = parent[k][v];
}
}
return parent[0][u];
}
int prev(int u, int k) {
if (parent.size() == 0) lca_build();
int K = parent.size();
for (int i = 0; i < K; i++) {
if ((k >> i) & 1) {
u = parent[i][u];
}
}
return u;
}
// 頂点 u から x 個親へ
int _prev(int u, int x) {
if (parent.size() == 0) lca_build();
int K = parent.size();
for (int k = 0; k < K; k++) {
if ((x >> k) & 1) {
u = parent[k][u];
}
}
return u;
}
T dist(int u, int v) {
if (weighted_dist.size() == 0) lca_build();
return weighted_dist[u] + weighted_dist[v] - 2 * weighted_dist[lca(u, v)];
}
};
int main() {
LL(N, Q);
Tree tree(N);
vll out(N, 0);
rep(i, N - 1) {
LL(A, B);
tree.add_edge(A - 1, B - 1);
out[A - 1]++;
out[B - 1]++;
}
auto count = tree.get_count();
while (Q--) {
LL(s, t); s--; t--;
ll dist = tree.dist(s, t);
if (dist % 2 != 0) {
OUT(0);
continue;
}
ll lca = tree.lca(s, t);
if (tree.dist(lca, s) < tree.dist(lca, t)) swap(s, t);
// s から dist / 2 個前の親
ll d = dist / 2;
ll c = tree.prev(s, d);
// c から出るs, t に行かない頂点の数
ll ans;
if (lca != c) {
// tree.prev(s, d - 1) が c の子
ans = count[c] - count[tree.prev(s, d - 1)];
} else {
ans = N - count[tree.prev(s, d - 1)] - count[tree.prev(t, d - 1)];
}
OUT(ans);
}
}