結果
| 問題 | No.2337 Equidistant |
| ユーザー |
👑  rin204
|
| 提出日時 | 2023-06-02 22:14:10 |
| 言語 | C++23 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 973 ms / 4,000 ms |
| コード長 | 11,530 bytes |
| コンパイル時間 | 4,001 ms |
| コンパイル使用メモリ | 264,720 KB |
| 実行使用メモリ | 38,536 KB |
| 最終ジャッジ日時 | 2024-12-28 18:42:04 |
| 合計ジャッジ時間 | 14,372 ms |
|
ジャッジサーバーID （参考情報） |
judge3 / judge4 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 1 |
| other | AC * 28 |
ソースコード
// start A.cpp
// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
template <class T>
using pq = priority_queue<T>;
template <class T>
using qp = priority_queue<T, vector<T>, greater<T>>;
#define vec(T, A, ...) vector<T> A(__VA_ARGS__);
#define vvec(T, A, h, ...) vector<vector<T>> A(h, vector<T>(__VA_ARGS__));
#define vvvec(T, A, h1, h2, ...) vector<vector<vector<T>>> A(h1, vector<vector<T>>(h2, vector<T>(__VA_ARGS__)));
#ifndef RIN__LOCAL
#define endl "\n"
#endif
#define spa ' '
#define len(A) A.size()
#define all(A) begin(A), end(A)
#define fori1(a) for (ll _ = 0; _ < (a); _++)
#define fori2(i, a) for (ll i = 0; i < (a); i++)
#define fori3(i, a, b) for (ll i = (a); i < (b); i++)
#define fori4(i, a, b, c) for (ll i = (a); ((c) > 0 || i > (b)) && ((c) < 0 || i < (b)); i += (c))
#define overload4(a, b, c, d, e, ...) e
#define fori(...) overload4(__VA_ARGS__, fori4, fori3, fori2, fori1)(__VA_ARGS__)
vector<char> stoc(string &S) {
int n = S.size();
vector<char> ret(n);
for (int i = 0; i < n; i++) ret[i] = S[i];
return ret;
}
#define INT(...) \
int __VA_ARGS__; \
inp(__VA_ARGS__);
#define LL(...) \
ll __VA_ARGS__; \
inp(__VA_ARGS__);
#define STRING(...) \
string __VA_ARGS__; \
inp(__VA_ARGS__);
#define CHAR(...) \
char __VA_ARGS__; \
inp(__VA_ARGS__);
#define VEC(T, A, n) \
vector<T> A(n); \
inp(A);
#define VVEC(T, A, n, m) \
vector<vector<T>> A(n, vector<T>(m)); \
inp(A);
const ll MOD1 = 1000000007;
const ll MOD9 = 998244353;
template <class T>
auto min(const T &a) {
return *min_element(all(a));
}
template <class T>
auto max(const T &a) {
return *max_element(all(a));
}
template <class T, class S>
auto clamp(T &a, const S &l, const S &r) {
return (a > r ? r : a < l ? l : a);
}
template <class T, class S>
inline bool chmax(T &a, const S &b) {
return (a < b ? a = b, 1 : 0);
}
template <class T, class S>
inline bool chmin(T &a, const S &b) {
return (a > b ? a = b, 1 : 0);
}
template <class T, class S>
inline bool chclamp(T &a, const S &l, const S &r) {
auto b = clamp(a, l, r);
return (a != b ? a = b, 1 : 0);
}
void FLUSH() {
cout << flush;
}
void print() {
cout << endl;
}
template <class Head, class... Tail>
void print(Head &&head, Tail &&... tail) {
cout << head;
if (sizeof...(Tail)) cout << spa;
print(forward<Tail>(tail)...);
}
template <typename T>
void print(vector<T> &A) {
int n = A.size();
for (int i = 0; i < n; i++) {
cout << A[i];
if (i != n - 1) cout << ' ';
}
cout << endl;
}
template <typename T>
void print(vector<vector<T>> &A) {
for (auto &row : A) print(row);
}
template <typename T, typename S>
void print(pair<T, S> &A) {
cout << A.first << spa << A.second << endl;
}
template <typename T, typename S>
void print(vector<pair<T, S>> &A) {
for (auto &row : A) print(row);
}
template <typename T, typename S>
void prisep(vector<T> &A, S sep) {
int n = A.size();
for (int i = 0; i < n; i++) {
cout << A[i];
if (i != n - 1) cout << sep;
}
cout << endl;
}
template <typename T, typename S>
void priend(T A, S end) {
cout << A << end;
}
template <typename T>
void priend(T A) {
priend(A, spa);
}
template <class... T>
void inp(T &... a) {
(cin >> ... >> a);
}
template <typename T>
void inp(vector<T> &A) {
for (auto &a : A) cin >> a;
}
template <typename T>
void inp(vector<vector<T>> &A) {
for (auto &row : A) inp(row);
}
template <typename T, typename S>
void inp(pair<T, S> &A) {
inp(A.first, A.second);
}
template <typename T, typename S>
void inp(vector<pair<T, S>> &A) {
for (auto &row : A) inp(row.first, row.second);
}
template <typename T>
T sum(vector<T> &A) {
T tot = 0;
for (auto a : A) tot += a;
return tot;
}
template <typename T>
vector<T> compression(vector<T> X) {
sort(all(X));
X.erase(unique(all(X)), X.end());
return X;
}
vector<vector<int>> read_edges(int n, int m, bool direct = false, int indexed = 1) {
vector<vector<int>> edges(n, vector<int>());
for (int i = 0; i < m; i++) {
INT(u, v);
u -= indexed;
v -= indexed;
edges[u].push_back(v);
if (!direct) edges[v].push_back(u);
}
return edges;
}
vector<vector<int>> read_tree(int n, int indexed = 1) {
return read_edges(n, n - 1, false, indexed);
}
template <typename T>
vector<vector<pair<int, T>>> read_wedges(int n, int m, bool direct = false, int indexed = 1) {
vector<vector<pair<int, T>>> edges(n, vector<pair<int, T>>());
for (int i = 0; i < m; i++) {
INT(u, v);
T w;
inp(w);
u -= indexed;
v -= indexed;
edges[u].push_back({v, w});
if (!direct) edges[v].push_back({u, w});
}
return edges;
}
template <typename T>
vector<vector<pair<int, T>>> read_wtree(int n, int indexed = 1) {
return read_wedges<T>(n, n - 1, false, indexed);
}
inline bool yes(bool f = true) {
cout << (f ? "yes" : "no") << endl;
return f;
}
inline bool Yes(bool f = true) {
cout << (f ? "Yes" : "No") << endl;
return f;
}
inline bool YES(bool f = true) {
cout << (f ? "YES" : "NO") << endl;
return f;
}
inline bool no(bool f = true) {
cout << (!f ? "yes" : "no") << endl;
return f;
}
inline bool No(bool f = true) {
cout << (!f ? "Yes" : "No") << endl;
return f;
}
inline bool NO(bool f = true) {
cout << (!f ? "YES" : "NO") << endl;
return f;
}
// start tree/LCA.hpp
struct LCA {
int n;
int logn;
vector<vector<int>> par;
vector<vector<int>> edges;
vector<int> depth;
LCA(int n) : n(n) {
logn = 0;
int x = 1;
while (x < n) {
x *= 2;
logn++;
}
par.assign(logn, vector<int>(n, -1));
edges.resize(n);
depth.assign(n, -1);
}
void read_edges(int indexed = 1) {
int u, v;
for (int i = 0; i < n - 1; i++) {
cin >> u >> v;
u -= indexed;
v -= indexed;
edges[u].push_back(v);
edges[v].push_back(u);
}
}
void add_edge(int u, int v) {
edges[u].push_back(v);
edges[v].push_back(u);
}
void build(int root = 0) {
stack<int> st;
st.push(root);
depth[root] = 0;
while (!st.empty()) {
int pos = st.top();
st.pop();
for (auto npos : edges[pos]) {
if (depth[npos] == -1) {
depth[npos] = depth[pos] + 1;
par[0][npos] = pos;
st.push(npos);
}
}
}
for (int i = 1; i < logn; i++) {
for (int j = 0; j < n; j++) {
int p = par[i - 1][j];
if (p != -1) {
par[i][j] = par[i - 1][p];
}
}
}
}
int lca(int u, int v) {
int du = depth[u];
int dv = depth[v];
if (du > dv) {
swap(u, v);
swap(du, dv);
}
int d = dv - du;
int i = 0;
while (d > 0) {
if (d & 1) v = par[i][v];
d >>= 1;
i++;
}
if (u == v) return u;
for (int i = logn - 1; i >= 0; i--) {
int pu = par[i][u];
int pv = par[i][v];
if (pu != pv) {
u = pu;
v = pv;
}
}
return par[0][u];
}
int dist(int u, int v) {
int p = lca(u, v);
return depth[u] + depth[v] - 2 * depth[p];
}
int jump(int u, int v, int k) {
if (k == 0) return u;
int p = lca(u, v);
int du = depth[u] - depth[p];
int dv = depth[v] - depth[p];
if (du + dv < k) return -1;
int d;
if (k <= du) {
d = k;
} else {
u = v;
d = du + dv - k;
}
int i = 0;
while (d > 0) {
if (d & 1) u = par[i][u];
d >>= 1;
i++;
}
return u;
}
};
// end tree/LCA.hpp
// restart A.cpp
void solve() {
INT(n, Q);
LCA G(n);
G.read_edges();
G.build();
vec(ll, siz, n, 1);
auto dfs = [&](auto &&self, int pos, int bpos) -> void {
for (auto npos : G.edges[pos]) {
if (npos == bpos) continue;
self(self, npos, pos);
siz[pos] += siz[npos];
}
};
dfs(dfs, 0, -1);
fori(Q) {
INT(u, v);
u--;
v--;
ll d = G.dist(u, v);
if (d & 1) {
print(0);
continue;
}
d /= 2;
int a = G.jump(u, v, d - 1);
int b = G.jump(u, v, d);
int c = G.jump(u, v, d + 1);
ll ans = n;
if (G.depth[a] > G.depth[b])
ans -= siz[a];
else
ans -= n - siz[b];
if (G.depth[c] > G.depth[b])
ans -= siz[c];
else
ans -= n - siz[b];
print(ans);
}
}
int main() {
cin.tie(0)->sync_with_stdio(0);
// cout << fixed << setprecision(12);
int t;
t = 1;
// cin >> t;
while (t--) solve();
return 0;
}
// end A.cpp