結果
| 問題 | No.2337 Equidistant |
| ユーザー |
 だれ
|
| 提出日時 | 2023-06-02 22:00:41 |
| 言語 | C++17 (gcc 12.3.0 + boost 1.83.0) |
| 結果 |
WA
|
| 実行時間 | - |
| コード長 | 7,890 bytes |
| コンパイル時間 | 3,648 ms |
| コンパイル使用メモリ | 196,660 KB |
| 実行使用メモリ | 51,768 KB |
| 最終ジャッジ日時 | 2024-06-08 23:05:51 |
| 合計ジャッジ時間 | 15,409 ms |
|
ジャッジサーバーID （参考情報） |
judge3 / judge4 |
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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
5,248 KB |
| testcase_01 | WA | - |
| testcase_02 | WA | - |
| testcase_03 | WA | - |
| testcase_04 | WA | - |
| testcase_05 | WA | - |
| testcase_06 | WA | - |
| testcase_07 | WA | - |
| testcase_08 | WA | - |
| testcase_09 | WA | - |
| testcase_10 | WA | - |
| testcase_11 | WA | - |
| testcase_12 | WA | - |
| testcase_13 | WA | - |
| testcase_14 | WA | - |
| testcase_15 | WA | - |
| testcase_16 | WA | - |
| testcase_17 | WA | - |
| testcase_18 | WA | - |
| testcase_19 | WA | - |
| testcase_20 | WA | - |
| testcase_21 | WA | - |
| testcase_22 | AC | 327 ms
40,764 KB |
| testcase_23 | WA | - |
| testcase_24 | WA | - |
| testcase_25 | WA | - |
| testcase_26 | WA | - |
| testcase_27 | WA | - |
| testcase_28 | WA | - |
ソースコード
#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <unordered_set>
using namespace std;
#if __has_include(<atcoder/all>)
#include <atcoder/all>
#endif
#define GET_MACRO(_1, _2, _3, NAME, ...) NAME
#define _rep(i, n) _rep2(i, 0, n)
#define _rep2(i, a, b) for (int i = (int)(a); i < (int)(b); i++)
#define rep(...) GET_MACRO(__VA_ARGS__, _rep2, _rep)(__VA_ARGS__)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define UNIQUE(x) \
std::sort((x).begin(), (x).end()); \
(x).erase(std::unique((x).begin(), (x).end()), (x).end())
using i64 = long long;
template <class T, class U>
bool chmin(T& a, const U& b) {
return (b < a) ? (a = b, true) : false;
}
template <class T, class U>
bool chmax(T& a, const U& b) {
return (b > a) ? (a = b, true) : false;
}
inline void YesNo(bool f = 0, string yes = "Yes", string no = "No") {
std::cout << (f ? yes : no) << "\n";
}
namespace io {
template <typename T>
istream& operator>>(istream& i, vector<T>& v) {
rep(j, v.size()) i >> v[j];
return i;
}
template <typename T>
string join(vector<T>& v) {
stringstream s;
rep(i, v.size()) s << ' ' << v[i];
return s.str().substr(1);
}
template <typename T>
ostream& operator<<(ostream& o, vector<T>& v) {
if (v.size()) o << join(v);
return o;
}
template <typename T>
string join(vector<vector<T>>& vv) {
string s = "\n";
rep(i, vv.size()) s += join(vv[i]) + "\n";
return s;
}
template <typename T>
ostream& operator<<(ostream& o, vector<vector<T>>& vv) {
if (vv.size()) o << join(vv);
return o;
}
template <class T, class U>
istream& operator>>(istream& i, pair<T, U>& p) {
i >> p.first >> p.second;
return i;
}
template <class T, class U>
ostream& operator<<(ostream& o, pair<T, U>& p) {
o << p.first << " " << p.second;
return o;
}
void print() { cout << "\n"; }
template <class Head, class... Tail>
void print(Head&& head, Tail&&... tail) {
cout << head;
if (sizeof...(tail)) cout << ' ';
print(std::forward<Tail>(tail)...);
}
void in() {}
template <class Head, class... Tail>
void in(Head&& head, Tail&&... tail) {
cin >> head;
in(std::forward<Tail>(tail)...);
}
} // namespace io
using namespace io;
namespace useful {
long long modpow(long long a, long long b, long long mod) {
long long res = 1;
while (b) {
if (b & 1) res *= a, res %= mod;
a *= a;
a %= mod;
b >>= 1;
}
return res;
}
bool is_pow2(long long x) { return x > 0 && (x & (x - 1)) == 0; }
template <class T>
void rearrange(vector<T>& a, vector<int>& p) {
vector<T> b = a;
for (int i = 0; i < int(a.size()); i++) {
a[i] = b[p[i]];
}
return;
}
template <class T>
vector<pair<int, int>> rle_sequence(T& a) {
vector<pair<int, int>> res;
int n = a.size();
if (n == 1) return vector<pair<int, int>>{{a[0], 1}};
int l = 1;
rep(i, n - 1) {
if (a[i] == a[i + 1])
l++;
else {
res.emplace_back(a[i], l);
l = 1;
}
}
res.emplace_back(a.back(), l);
return res;
}
vector<pair<char, int>> rle_string(string a) {
vector<pair<char, int>> res;
int n = a.size();
if (n == 1) return vector<pair<char, int>>{{a[0], 1}};
int l = 1;
rep(i, n - 1) {
if (a[i] == a[i + 1])
l++;
else {
res.emplace_back(a[i], l);
l = 1;
}
}
res.emplace_back(a.back(), l);
return res;
}
vector<int> linear_sieve(int n) {
vector<int> primes;
vector<int> res(n + 1);
iota(all(res), 0);
for (int i = 2; i <= n; i++) {
if (res[i] == i) primes.emplace_back(i);
for (auto j : primes) {
if (j * i > n) break;
res[j * i] = j;
}
}
return res;
// return primes;
}
template <class T>
vector<long long> dijkstra(vector<vector<pair<int, T>>>& graph, int start) {
int n = graph.size();
vector<long long> res(n, 2e18);
res[start] = 0;
priority_queue<pair<long long, int>, vector<pair<long long, int>>,
greater<pair<long long, int>>>
que;
que.push({0, start});
while (!que.empty()) {
auto [c, v] = que.top();
que.pop();
if (res[v] < c) continue;
for (auto [nxt, cost] : graph[v]) {
auto x = c + cost;
if (x < res[nxt]) {
res[nxt] = x;
que.push({x, nxt});
}
}
}
return res;
}
} // namespace useful
using namespace useful;
struct LowestCommonAncestor {
using G = vector<vector<int>>;
private:
const G& graph;
const int n;
vector<int> depth;
vector<vector<int>> table;
const int log = 20;
inline void bfs(int st) {
depth[st] = 0;
queue<int> que;
que.emplace(st);
while (!que.empty()) {
auto now = que.front();
que.pop();
for (auto e : graph[now]) {
if (depth[e] != -1) continue;
depth[e] = depth[now] + 1;
table[e][0] = now;
que.emplace(e);
}
}
}
public:
LowestCommonAncestor(const G& g, int root = 0) : graph(g), n(g.size()) {
depth = vector<int>(n, -1);
table = vector(n, vector<int>(log, -1));
bfs(root);
for (int k = 0; k < log - 1; k++) {
for (int i = 0; i < n; i++) {
if (table[i][k] == -1)
table[i][k + 1] = -1;
else
table[i][k + 1] = table[table[i][k]][k];
}
}
}
int LCA(int a, int b) {
if (depth[a] < depth[b]) swap(a, b);
for (int i = log - 1; i >= 0; i--) {
if ((depth[a] - depth[b]) >> i & 1) a = table[a][i];
}
if (a == b) return a;
for (int i = log - 1; i >= 0; i--) {
if (table[a][i] != table[b][i]) {
a = table[a][i];
b = table[b][i];
}
}
return table[a][0];
}
int distance(int u, int v) {
return depth[u] + depth[v] - 2 * depth[LCA(u, v)];
}
int la(int x, int k) {
for (int i = 0; i < log; i++) {
if (k >> i & 1) {
x = table[x][i];
}
}
return x;
}
};
vector<vector<int>> e;
int c_sz[200010];
int dfs(int now, int p) {
c_sz[now] = 1;
for (auto j : e[now]) {
if (j == p) continue;
c_sz[now] += dfs(j, now);
}
return c_sz[now];
}
int main() {
cin.tie(nullptr);
ios::sync_with_stdio(false);
int n, q;
in(n, q);
e.resize(n);
rep(i, n - 1) {
int a, b;
in(a, b);
a--, b--;
e[a].emplace_back(b);
e[b].emplace_back(a);
}
LowestCommonAncestor lca(e);
dfs(0, -1);
while (q--) {
int s, t;
in(s, t);
s--, t--;
auto l = lca.LCA(s, t);
auto ds = lca.distance(l, s);
auto dt = lca.distance(l, t);
if ((ds & 1) != (dt & 1)) {
print(0);
continue;
}
if (ds < dt) {
swap(s, t);
swap(ds, dt);
}
if (ds == dt) {
auto ss = lca.la(s, ds - 1);
auto tt = lca.la(t, dt - 1);
print(n - c_sz[ss] - c_sz[tt]);
continue;
}
int b = (ds - dt) / 2;
int dcenter = ds - b;
int center = lca.la(s, dcenter);
int cen_to_s = lca.la(s, dcenter - 1);
print(c_sz[center] + 1 - c_sz[cen_to_s]);
}
}