結果
| 問題 |
No.1326 ふたりのDominator
|
| コンテスト | |
| ユーザー |
 emthrm
|
| 提出日時 | 2020-12-23 00:33:50 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 170 ms / 2,000 ms |
| コード長 | 9,743 bytes |
| コンパイル時間 | 3,254 ms |
| コンパイル使用メモリ | 228,876 KB |
| 最終ジャッジ日時 | 2025-01-17 06:17:08 |
|
ジャッジサーバーID （参考情報） |
judge5 / judge3 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 1 |
| other | AC * 24 |
ソースコード
#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
constexpr int dy[] = {1, 0, -1, 0}, dx[] = {0, -1, 0, 1};
constexpr int dy8[] = {1, 1, 0, -1, -1, -1, 0, 1}, dx8[] = {0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U> inline bool chmax(T &a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U> inline bool chmin(T &a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
IOSetup() {
std::cin.tie(nullptr);
std::ios_base::sync_with_stdio(false);
std::cout << fixed << setprecision(20);
}
} iosetup;
struct Lowlink {
std::vector<std::vector<int>> graph;
std::vector<int> ap;
std::vector<std::pair<int, int>> bridge;
Lowlink(const std::vector<std::vector<int>> &graph) : graph(graph) {
int n = graph.size();
order.assign(n, -1);
lowlink.resize(n);
int tm = 0;
for (int i = 0; i < n; ++i) {
if (order[i] == -1) dfs(-1, i, tm);
}
// std::sort(ap.begin(), ap.end());
// std::sort(bridge.begin(), bridge.end(), [](const pair<int, int> &a, const pair<int, int> &b) -> bool {
// int as, ad, bs, bd;
// std::tie(as, ad) = a;
// std::tie(bs, bd) = b;
// return as != bs ? as < bs : ad < bd;
// });
}
std::vector<int> order, lowlink;
private:
void dfs(int par, int ver, int &tm) {
order[ver] = lowlink[ver] = tm++;
int cnt = 0;
bool is_ap = false;
for (int e : graph[ver]) {
if (order[e] == -1) {
++cnt;
dfs(ver, e, tm);
if (lowlink[e] < lowlink[ver]) lowlink[ver] = lowlink[e];
if (order[ver] <= lowlink[e]) {
is_ap = true;
if (order[ver] < lowlink[e]) bridge.emplace_back(std::minmax(ver, e));
}
} else if (e != par) {
if (order[e] < lowlink[ver]) lowlink[ver] = order[e];
}
}
if (par == -1) {
if (cnt >= 2) ap.emplace_back(ver);
} else {
if (is_ap) ap.emplace_back(ver);
}
}
};
struct BiconnectedComponent : Lowlink {
std::vector<std::vector<std::pair<int, int>>> block;
std::vector<int> id;
std::vector<std::vector<int>> vertices, cutpoint;
BiconnectedComponent(const std::vector<std::vector<int>> &graph, bool heavy = false) : Lowlink(graph), heavy(heavy) {
int n = graph.size();
id.assign(n, -2);
if (heavy) {
cutpoint.resize(n);
is_ap.assign(n, false);
for (int e : this->ap) is_ap[e] = true;
}
for (int i = 0; i < n; ++i) {
if (id[i] == -2) {
id[i] = -1;
dfs(-1, i);
}
}
// if (heavy) {
// int sz = vertices.size();
// for (int i = 0; i < sz; ++i) {
// std::sort(block[i].begin(), block[i].end());
// std::sort(vertices[i].begin(), vertices[i].end());
// }
// for (int i = 0; i < n; ++i) std::sort(cutpoint[i].begin(), cutpoint[i].end());
// }
}
private:
using P = std::pair<int, int>;
bool heavy;
std::vector<bool> is_ap;
std::vector<P> tmp;
void dfs(int par, int ver) {
for (int e : this->graph[ver]) {
if (e == par) continue;
if (id[e] == -2 || this->order[ver] > this->order[e]) tmp.emplace_back(std::minmax(ver, e));
if (id[e] == -2) {
id[e] = -1;
dfs(ver, e);
if (this->order[ver] <= this->lowlink[e]) {
int idx = block.size();
block.emplace_back();
std::set<int> st;
while (true) {
P pr = tmp.back();
block[idx].emplace_back(pr);
if (heavy) {
st.emplace(pr.first);
st.emplace(pr.second);
}
tmp.pop_back();
if (pr.first == std::min(ver, e) && pr.second == std::max(ver, e)) break;
}
if (heavy) {
vertices.emplace_back();
for (int el : st) {
vertices[idx].emplace_back(el);
if (is_ap[el]) {
cutpoint[el].emplace_back(idx);
} else {
id[el] = idx;
}
}
}
}
}
}
}
};
struct HLD {
std::vector<int> parent, subtree, id, inv, head;
HLD(const std::vector<std::vector<int>> &graph, int root = 0) : graph(graph) {
int n = graph.size();
parent.assign(n, -1);
subtree.assign(n, 1);
id.resize(n);
inv.resize(n);
head.resize(n);
dfs1(root);
head[root] = root;
int now_id = 0;
dfs2(root, now_id);
}
template <typename Fn>
void v_update(int u, int v, Fn f) const {
while (true) {
if (id[u] > id[v]) std::swap(u, v);
f(std::max(id[head[v]], id[u]), id[v] + 1);
if (head[u] == head[v]) return;
v = parent[head[v]];
}
}
template <typename T, typename F, typename G>
T v_query(int u, int v, F f, G g, const T UNITY) const {
T left = UNITY, right = UNITY;
while (true) {
if (id[u] > id[v]) {
std::swap(u, v);
std::swap(left, right);
}
left = g(left, f(std::max(id[head[v]], id[u]), id[v] + 1));
if (head[u] == head[v]) break;
v = parent[head[v]];
}
return g(left, right);
}
template <typename Fn>
void subtree_v_update(int ver, Fn f) const { f(id[ver], id[ver] + subtree[ver]); }
template <typename T, typename Fn>
T subtree_v_query(int ver, Fn f) const { return f(id[ver], id[ver] + subtree[ver]); }
template <typename Fn>
void e_update(int u, int v, Fn f) const {
while (true) {
if (id[u] > id[v]) std::swap(u, v);
if (head[u] == head[v]) {
f(id[u], id[v]);
break;
} else {
f(id[head[v]] - 1, id[v]);
v = parent[head[v]];
}
}
}
template <typename T, typename F, typename G>
T e_query(int u, int v, F f, G g, const T UNITY) const {
T left = UNITY, right = UNITY;
while (true) {
if (id[u] > id[v]) {
std::swap(u, v);
std::swap(left, right);
}
if (head[u] == head[v]) {
left = g(left, f(id[u], id[v]));
break;
} else {
left = g(left, f(id[head[v]] - 1, id[v]));
v = parent[head[v]];
}
}
return g(left, right);
}
template <typename Fn>
void subtree_e_update(int ver, Fn f) const { f(id[ver], id[ver] + subtree[ver] - 1); }
template <typename T, typename Fn>
T subtree_e_query(int ver, Fn f) const { return f(id[ver], id[ver] + subtree[ver] - 1); }
int lca(int u, int v) const {
while (true) {
if (id[u] > id[v]) std::swap(u, v);
if (head[u] == head[v]) return u;
v = parent[head[v]];
}
}
private:
std::vector<std::vector<int>> graph;
void dfs1(int ver) {
for (int &e : graph[ver]) {
if (e != parent[ver]) {
parent[e] = ver;
dfs1(e);
subtree[ver] += subtree[e];
if (subtree[e] > subtree[graph[ver].front()]) std::swap(e, graph[ver].front());
}
}
}
void dfs2(int ver, int &now_id) {
id[ver] = now_id++;
inv[id[ver]] = ver;
for (int e : graph[ver]) {
if (e != parent[ver]) {
head[e] = (e == graph[ver].front() ? head[ver] : e);
dfs2(e, now_id);
}
}
}
};
template <typename Semigroup, typename Fn>
struct DisjointSparseTable {
DisjointSparseTable(const std::vector<Semigroup> &a, Fn fn) : fn(fn) {
int n = a.size(), table_h = 1;
while ((1 << table_h) < n) ++table_h;
lg.assign(1 << table_h, 0);
for (int i = 2; i < (1 << table_h); ++i) lg[i] = lg[i >> 1] + 1;
dat.assign(table_h, std::vector<Semigroup>(n));
for (int j = 0; j < n; ++j) dat[0][j] = a[j];
for (int i = 1; i < table_h; ++i) {
int shift = 1 << i;
for (int left = 0; left < n; left += shift << 1) {
int mid = std::min(left + shift, n);
dat[i][mid - 1] = a[mid - 1];
for (int j = mid - 2; j >= left; --j) dat[i][j] = fn(a[j], dat[i][j + 1]);
if (n <= mid) break;
int right = std::min(mid + shift, n);
dat[i][mid] = a[mid];
for (int j = mid + 1; j < right; ++j) dat[i][j] = fn(dat[i][j - 1], a[j]);
}
}
}
Semigroup query(int left, int right) const {
assert(left < right);
if (left == --right) return dat[0][left];
int h = lg[left ^ right];
return fn(dat[h][left], dat[h][right]);
}
private:
Fn fn;
std::vector<int> lg;
std::vector<std::vector<Semigroup>> dat;
};
int main() {
int n, m; cin >> n >> m;
vector<vector<int>> graph(n);
while (m--) {
int u, v; cin >> u >> v; --u; --v;
graph[u].emplace_back(v);
graph[v].emplace_back(u);
}
BiconnectedComponent bc(graph, true);
int b = bc.block.size(), a = bc.ap.size();
vector<vector<int>> bctree(b + a);
REP(i, a) for (int e : bc.cutpoint[bc.ap[i]]) {
bctree[bc.block.size() + i].emplace_back(e);
bctree[e].emplace_back(bc.block.size() + i);
}
vector<int> rev(n, -1);
REP(i, a) rev[bc.ap[i]] = i;
HLD hld(bctree);
vector<int> w(b + a, 0);
FOR(i, b, b + a) w[hld.id[i]] = 1;
DisjointSparseTable dst(w, [](int a, int b) -> int { return a + b; });
int q; cin >> q;
while (q--) {
int x, y; cin >> x >> y; --x; --y;
if (x == y) {
cout << 0 << '\n';
continue;
}
x = rev[x] == -1 ? bc.id[x] : b + rev[x];
y = rev[y] == -1 ? bc.id[y] : b + rev[y];
int ans = hld.v_query(x, y, [&](int l, int r) { return dst.query(l, r); }, [](int a, int b) { return a + b; }, 0);
ans -= (x >= b) + (y >= b);
cout << ans << '\n';
}
return 0;
}