//#define NDEBUG
#include <bits/stdc++.h>
#include <bits/extc++.h>
#define StarBurstStream ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define iter(a) a.begin(), a.end()
#define riter(a) a.rbegin(), a.rend()
#define lsort(a) sort(iter(a))
#define gsort(a) sort(riter(a))
#define pb(a) push_back(a)
#define eb(a) emplace_back(a)
#define pf(a) push_front(a)
#define pob pop_back()
#define pof pop_front()
#define mp(a, b) make_pair(a, b)
#define F first
#define S second
#define mt make_tuple
#define gt(t, i) get<i>(t)
#define iceil(a, b) (((a) + (b) - 1) / (b))
#define tomax(a, b) ((a) = max((a), (b)))
#define printv(a, b) {bool pvaspace=false; \
for(auto pva : a){ \
if(pvaspace) b << " "; pvaspace=true;\
b << pva;\
}\
b << "\n";}
//#define TEST
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pdd = pair<ld, ld>;
using tiii = tuple<int, int, int>;
const ll MOD = 1000000007;
const ll MAX = 2147483647;
template<typename A, typename B>
ostream& operator<<(ostream& o, pair<A, B> p){
return o << '(' << p.F << ',' << p.S << ')';
}
vector<vector<int>> tg, g;
int bcc;
vector<int> low, in;
int tts = 1;
stack<int> st;
vector<vector<int>> c;
vector<bool> iscut;
void dfsbcc(int now, int p){
low[now] = in[now] = tts++;
for(int i : tg[now]){
if(i == p) continue;
if(in[i]) low[now] = min(low[now], in[i]);
else{
dfsbcc(i, now);
low[now] = min(low[now], low[i]);
c[now].eb(i);
}
if(low[i] >= in[now] && now != 1) iscut[now] = true;
}
if(now == 1 && c[now].size() > 1) iscut[now] = true;
}
void dfsbcc2(int now, int p){
st.push(now);
for(int i : c[now]){
dfsbcc2(i, now);
}
if(now == 1){
if(st.size() > 1){
while(!st.empty()){
g[st.top()].eb(bcc);
g[bcc].eb(st.top());
st.pop();
}
bcc++;
}
}
else if((p != 1 && low[now] >= in[p]) || (p == 1 && c[p].size() > 1)){
while(!st.empty()){
int t = st.top();
g[st.top()].eb(bcc);
g[bcc].eb(st.top());
st.pop();
if(t == now) break;
}
g[bcc].eb(p);
g[p].eb(bcc);
bcc++;
}
}
vector<int> sz, cnt;
ll ans = 0;
void dfs1(int now, int p){
sz[now] = cnt[now];
for(int i : g[now]){
if(i == p) continue;
dfs1(i, now);
sz[now] += sz[i];
}
}
int n;
void dfs2(int now, int p, int r){
for(int i : g[now]){
if(i == p) continue;
ans += (ll) cnt[now] * sz[i] * (sz[r] - cnt[now] - sz[i]);
ans += (ll) cnt[now] * (cnt[now] - 1) * sz[i] * 2;
ans += (ll) cnt[now] * cnt[i] * (cnt[i] - 1);
// cerr << now << " " << i << " " << r << " " << cnt[now] << " " << sz[i] << " " << sz[r] << "\n";
cerr << now << " " << i << " " <<(ll) cnt[now] * sz[i] * (sz[r] - cnt[now] - sz[i]) << " " << (ll) cnt[now] * (cnt[now] - 1) * sz[i] * 2 << "\n";
dfs2(i, now, r);
}
ans += (ll) cnt[now] * (sz[r] - sz[now]) * (sz[now] - cnt[now]);
ans += (ll) cnt[now] * (cnt[now] - 1) * (sz[r] - sz[now]) * 2;
ans += (ll) cnt[now] * (cnt[now] - 1) * (cnt[now] - 2);
// cerr << "test " << now << " " <<(ll) cnt[now] * (sz[r] - sz[now]) * (sz[now] - cnt[now]) << " " << (ll) cnt[now] * (cnt[now] - 1) * (sz[r] - sz[now]) * 2 << " "
// << (ll) cnt[now] * (cnt[now] - 1) * (cnt[now] - 2) << "\n";
}
int main(){
StarBurstStream
int m;
cin >> n >> m;
tg.resize(n + 1);
g.resize(3 * n + 1);
bcc = n + 1;
low.resize(n + 1);
in.resize(n + 1);
c.resize(n + 1);
iscut.resize(n + 1);
for(int i = 0; i < m; i++){
int u, v;
cin >> u >> v;
tg[u].eb(v);
tg[v].eb(u);
}
for(int i = 1; i <= n; i++){
if(in[i]) continue;
dfsbcc(i, i);
dfsbcc2(i, i);
}
// for(int i = 1; i <= n; i++){
// cerr << i << " ";
// printv(g[i], cerr);
// }
sz.resize(3 * n + 1, -1);
cnt.resize(3 * n + 1);
for(int i = n + 1; i < bcc; i++){
for(int j : g[i]){
if(!iscut[j]) cnt[i]++;
}
}
for(int i = 1; i <= n; i++) if(iscut[i]) cnt[i] = 1;
for(int i = 1; i < bcc; i++){
if(sz[i] != -1) continue;
dfs1(i, i);
dfs2(i, i, i);
}
cout << ans << "\n";
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1077 ms |
36752 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
38 ms |
640 KB |
Output is correct |
| 2 |
Correct |
36 ms |
640 KB |
Output is correct |
| 3 |
Correct |
36 ms |
640 KB |
Output is correct |
| 4 |
Correct |
37 ms |
768 KB |
Output is correct |
| 5 |
Correct |
35 ms |
760 KB |
Output is correct |
| 6 |
Correct |
36 ms |
764 KB |
Output is correct |
| 7 |
Correct |
35 ms |
768 KB |
Output is correct |
| 8 |
Correct |
36 ms |
764 KB |
Output is correct |
| 9 |
Correct |
35 ms |
640 KB |
Output is correct |
| 10 |
Correct |
36 ms |
640 KB |
Output is correct |
| 11 |
Correct |
35 ms |
672 KB |
Output is correct |
| 12 |
Correct |
35 ms |
640 KB |
Output is correct |
| 13 |
Correct |
36 ms |
760 KB |
Output is correct |
| 14 |
Incorrect |
36 ms |
640 KB |
Output isn't correct |
| 15 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1059 ms |
28860 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
35 ms |
640 KB |
Output is correct |
| 2 |
Correct |
35 ms |
640 KB |
Output is correct |
| 3 |
Incorrect |
33 ms |
640 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1087 ms |
27604 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
