#ifdef local
#define _GLIBCXX_DEBUG 1
#endif
#pragma GCC optimize("Ofast", "unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define int int64_t
#define double long double
using pii = pair<int, int>;
template <typename T>
using Prior = std::priority_queue<T>;
template <typename T>
using prior = std::priority_queue<T, vector<T>, greater<T>>;
// #define X first
// #define Y second
#define eb emplace_back
#define ef emplace_front
#define ee emplace
#define pb pop_back
#define pf pop_front
#define ALL(x) begin(x), end(x)
#define RALL(x) rbegin(x), rend(x)
#define SZ(x) ((int)(x).size())
#ifdef local
#define fastIO() void()
#define debug(...) \
_color.eb("\u001b[31m"),\
cerr << _color.back() << "At [" << __FUNCTION__ << "], line " << __LINE__ << ": ",\
cerr << "(" << #__VA_ARGS__ << ") = ", _do(__VA_ARGS__),\
_color.pb(),\
cerr << _color.back()
deque<string> _color{"\u001b[0m"};
template <typename T> concept is_string = is_same_v<T, string&> or is_same_v<T, const string&>;
template <typename T> concept is_iterable = requires (T _t) {begin(_t);};
template <typename T> inline void _print_err(T &&_t) {cerr << _t;}
template <typename T> inline void _print_err(T &&_t) requires is_iterable<T> and (not is_string<T>) {
string _tmp_color = _color.back();
++_tmp_color[3], _color.eb(_tmp_color);
cerr << _color.back() << "[";
for (bool _first = true; auto &_x : _t) {
if (!_first) cerr << ", ";
_print_err(_x), _first = false;
}
cerr << "]" << (_color.pb(), _color.back());
}
template <typename T, typename U> ostream& operator << (ostream &os, pair<T, U> &_tu) {
string _tmp_color = _color.back();
++_tmp_color[3], _color.eb(_tmp_color);
cerr << _color.back() << "(";
_print_err(_tu.first), cerr << ", ", _print_err(_tu.second);
cerr << ")" << (_color.pb(), _color.back());
return os;
}
template <size_t I = 0, typename ...U> inline typename enable_if<I == sizeof...(U), void>::type _print_err(tuple<U...> &) {
cerr << ")" << (_color.pb(), _color.back());
}
template <size_t I = 0, typename ...U> inline typename enable_if<I < sizeof...(U), void>::type _print_err(tuple<U...> &_t) {
if (!I) {
string _tmp_color = _color.back();
++_tmp_color[3], _color.eb(_tmp_color);
cerr << _color.back();
}
cerr << (I ? ", " : "("), _print_err(get<I>(_t)), _print_err<I+1, U...>(_t);
}
template <typename T> inline void _do(T &&_t) {_print_err(_t), cerr << "\n";}
template <typename T, typename ...U> inline void _do(T &&_t, U &&..._u) {_print_err(_t), cerr << ", ", _do(_u...);}
#else
#define fastIO() ios_base::sync_with_stdio(0), cin.tie(0)
#define debug(...) void()
#endif
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
inline int getRand(int L, int R) {
if (L > R) swap(L, R);
return (int)(rng() % ((uint64_t)R - L + 1) + L);
}
template <typename T, typename U> bool chmin(T &lhs, U rhs) {return lhs > rhs ? lhs = rhs, 1 : 0;}
template <typename T, typename U> bool chmax(T &lhs, U rhs) {return lhs < rhs ? lhs = rhs, 1 : 0;}
const int maxn = 1E5 + 5;
vector<int> adj[maxn], dfn, low;
vector<int> bct[2*maxn];
deque<int> stk;
void Tarjan(int now, int &tok_dfn, int &tok_bcc) {
dfn[now] = low[now] = tok_dfn++;
stk.eb(now);
int cnt_ch = 0;
for (int x : adj[now]) {
if (!~dfn[x]) {
++cnt_ch;
Tarjan(x, tok_dfn, tok_bcc);
chmin(low[now], low[x]);
// debug(now, x, dfn[now], low[x], stk);
if (low[x] >= dfn[now]) {
int p;
while ((p = stk.back()) != x) {
bct[p].eb(tok_bcc), bct[tok_bcc].eb(p), stk.pb();
}
bct[p].eb(tok_bcc), bct[tok_bcc].eb(p), stk.pb();
bct[now].eb(tok_bcc), bct[tok_bcc].eb(now);
++tok_bcc;
}
}
chmin(low[now], dfn[x]);
}
// debug(now, dfn[now], low[now]);
}
void solve() {
int N, M; cin >> N >> M;
for (int i = 0, u, v; i < M; ++i) {
cin >> u >> v, --u, --v;
adj[u].eb(v), adj[v].eb(u);
}
dfn.assign(N, -1), low.resize(N);
int tok_bcc = N;
for (int i = 0, tok_dfn = 0; i < N; ++i) {
if (!~dfn[i]) stk.clear(), Tarjan(i, tok_dfn, tok_bcc);
}
for (int i = N; i < tok_bcc; ++i) debug(i, bct[i]);
/// calculate answer in Block-Cut Tree ///
vector<int> vis(tok_bcc, 0), sz(tok_bcc, 0), sub(tok_bcc, 0);
/// size of ap = 1; size of bcc = (# of vertex) - (# of ap) ///
for (int i = 0; i < N; ++i) ++sz[SZ(bct[i]) == 1 ? bct[i][0] : i];
int ans = 0;
for (int i = 0; i < N; ++i) {
if (vis[i]) continue;
auto get_sz_ = [&](auto &&get_sz, int now, int fa) -> void {
vis[now] = true, sub[now] = sz[now];
for (int x : bct[now]) {
if (x == fa) continue;
get_sz(get_sz, x, now), sub[now] += sub[x];
}
debug(now, fa, sz[now], sub[now], bct[now]);
};
get_sz_(get_sz_, i, -1);
int sz_all = sub[i];
auto dfs_ = [&](auto &&dfs, int now, int fa) -> void {
for (int x : bct[now]) if (x != fa) dfs(dfs, x, now);
// debug("before"s, now, ans);
/// pick (s, c, f) in this {bcc `now` \ ap} ///
ans += sz[now] * (sz[now] - 1) * (sz[now] - 2);
/// pick (s, c) in this {bcc `now` \ ap}; (f) in other place (*2 because symmetric) ///
ans += sz[now] * (sz[now] - 1) * (sz_all - sz[now]) * 2;
/// pick (s) in child `fa`; (c) in this ap or {bcc `now` \ ap}; (f) in other children ///
ans += (sz_all - sub[now]) * sz[now] * (sub[now] - sz[now]);
for (int x : bct[now]) {
/// pick (s) in child `x`; (c) in this ap or {bcc `now` \ ap}; (f) in other children ///
if (x != fa) ans += sub[x] * sz[now] * (sz_all - sz[now] - sub[x]);
/// pick (s) in {bcc `x` \ `now`}; (c) in this ap; (f) in child `x` (*2 because symmetric) ///
ans += (SZ(bct[x]) - 1) * (now < N and SZ(bct[now]) > 1) * (sub[x] - 1) * 2;
/// minus f-s-c case (*2 because symmetric) ///
}
// debug(" after"s, now, ans);
};
dfs_(dfs_, i, -1);
}
cout << ans << "\n";
}
int32_t main() {
fastIO();
int t = 1; // cin >> t;
for (int _ = 1; _ <= t; ++_) {
// cout << "Case #" << _ << ": ";
solve();
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
7252 KB |
Output is correct |
2 |
Correct |
4 ms |
7252 KB |
Output is correct |
3 |
Correct |
4 ms |
7344 KB |
Output is correct |
4 |
Correct |
4 ms |
7372 KB |
Output is correct |
5 |
Correct |
4 ms |
7252 KB |
Output is correct |
6 |
Correct |
4 ms |
7252 KB |
Output is correct |
7 |
Incorrect |
5 ms |
7368 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
7252 KB |
Output is correct |
2 |
Correct |
4 ms |
7252 KB |
Output is correct |
3 |
Correct |
4 ms |
7344 KB |
Output is correct |
4 |
Correct |
4 ms |
7372 KB |
Output is correct |
5 |
Correct |
4 ms |
7252 KB |
Output is correct |
6 |
Correct |
4 ms |
7252 KB |
Output is correct |
7 |
Incorrect |
5 ms |
7368 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
76 ms |
29588 KB |
Output is correct |
2 |
Correct |
79 ms |
29740 KB |
Output is correct |
3 |
Incorrect |
103 ms |
26636 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
5 ms |
7508 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
114 ms |
24408 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
5 ms |
7508 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
103 ms |
24560 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
7252 KB |
Output is correct |
2 |
Correct |
4 ms |
7252 KB |
Output is correct |
3 |
Correct |
4 ms |
7344 KB |
Output is correct |
4 |
Correct |
4 ms |
7372 KB |
Output is correct |
5 |
Correct |
4 ms |
7252 KB |
Output is correct |
6 |
Correct |
4 ms |
7252 KB |
Output is correct |
7 |
Incorrect |
5 ms |
7368 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
7252 KB |
Output is correct |
2 |
Correct |
4 ms |
7252 KB |
Output is correct |
3 |
Correct |
4 ms |
7344 KB |
Output is correct |
4 |
Correct |
4 ms |
7372 KB |
Output is correct |
5 |
Correct |
4 ms |
7252 KB |
Output is correct |
6 |
Correct |
4 ms |
7252 KB |
Output is correct |
7 |
Incorrect |
5 ms |
7368 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |